AP Rotational Motion Updates

See Honors Post of today 12/30 for updated definitions and notes on angular quantities and rotational motion and torque.

Honors New Rotational Motion Schedule and Sheets

Here are new schedule and notes and problem sheet links . Lots of changes to schedule; changes to definitions and notes; changes to notes should make them easier for you to understand. R-3 hasn't changed from original post, just here for convenience. On the planet worksheet make sure you find and open the planet data form sheet

HonorsUnit7Rotsch07-8r1.doc

RotMotionDefseetc-07.doc

NotesonTorquerev12-30.doc

PlanetWS.xls

ProblemSheetR-1rev1.doc

ProblemSheetR-2.doc

ProblemSheetR-3.doc

Honors and Mathematical Quizzes

There will be brief quizzes tomorrow:

Honors on circular motion;

Mathematical on derivation of equation for finding vinitial

AP Fluids Solutions

Here is the link to my solutions to the text problems on fluids. Use a little a caution, I may be careless at times.

Solutionstotext.doc

Centripetal Force Lab

Centripetal Force Lab writeups can be informal

Urgent (well, sort of) AP Year End Schedule

Somehow our server managed to combine two  schedules and upload a garbled mess. ( I think there is a "buffer" that stores intermediate unsaved versions of documents and then when the occasional failure occurs substitutes the version stored in the buffer for the one that was supposed to be saved.) I have since uploaded the correct schedule. try the link now

Honors and Mathematical projects

Turn in your proposals for a project tomorrow or Wednesday the latest. A poster or a constructed object with explanation on some topic we have covered or will cover this semester.

Honors Schedule for Unit 7 Rotational Motion

Here are links for the new schedule and for the materials you will need now. Watch for future posts of additional material.

HonorsUnit7Rotsch07-8.doc

RotMotionDefseetc-07.doc
ProblemSheetR-3.doc

NotesonTorquerev12-30.doc

AP Fluids extra problems

Here are some extra problems for the gluttons amongst you.

Unit7ExtraProblems.doc

Honors Quiz

AP Fluids Practice problems #4

There is a typo in Problem 4 of the Fluids practice problems . In parentheses it should say:
1.013 E5 = 1 Pascal

AP New Schedule

Here is a new schedule to take you through the next two weeks. Do keep checking the blog, you never know what goodies may appear

APYearendsched07-8.doc

Honors Homework, new Fusion Fuel Calculation

Homework for Monday.

Use the blog if you can understand it, but the fact that this blog can't show exponents or subscripts makes it hard. Here is a link to the same information in a Word document.

DHe3problem.doc

which should be easy to follow.

Follow the process, and make sure you understand it, don’t just fill in the blanks blindly. There will be a quiz on this early this week.

The deuterium - helium 3 (D He3) reaction is perhaps the most desirable of all the easily achievable ones. The products are helium 4 and a proton. These particles are charged and can be confined by magnetic fields. They also do not interact with nuclei in the materials around them ( i.e., the reactor vessel) to make them radioactive.

Let’s investigate how many reactions per second and then how many fuel nuclei per m3 it would take for a D He 3 fueled power plant to put out 1 billion watts. Assume 40% efficiency so we need

10E9(J /sec )/.4 = ____ joules /sec of energy from the reactions.

Each reaction produces 18.4 MeV or ______J

The number of reactions per sec x the energy per reaction = energy per sec from the reactions.
Therefore the number of reactions we need per second is found from

________/_________ = _________ reactions per second

This reactor will have to be substantially larger than the deuterium tritium reactor we talked about Friday; lets say 250 m3 instead of 100 m3. The number of reactions we will need per m3 per sec is simply the number of reactions per sec / volume of reactor. So in this case the required reaction rate = _________ reactions per sec per m3.

Remembering that the reaction rate i.e. the number of reactions per m3 per sec is given by the number of “bullets” times their speed times the number of targets x the area per target, i.e. we have:

reaction rate [reactions/(m3s)] = nD vD nHe3 sigma; where n is the number of nuclei per m3 (number density), vD is the average speed of the deuterium nuclei and sigma is the target area per nucleus. Recall that for maximum reaction rate we set the two “n”s equal to each other and therefore each n = 1/2 the total fuel density or nD = nHe3= nfuel/2.

Lets look at the velocity. With the DHe3 reaction we have one nucleon with one proton and one neutron, the D: and one nucleon with two protons and one neutron, the He3. Therefore the potential energy when the two fuel nuclei approach each other is now given by PE = kcQ1Q2/r [kc = 9 billion or 9E9]

9E9x1.6E-19 x 2x1.6E-19/ r . If we approximate r as 2.E-14 [ this may be a poor estimate and we will discuss the details of this tomorrow] we get PE = ______J.

This PE of the nuclei as they reach this close distance, must be equal to the KE they started with, so we can use this KE and the fact that mD x vD2/2 = KE to find vD of the deuterons circulating in the reactor. Recall that the mass of a deuteron, which contains two nucleons, is 2 x 1.67E-27, and rewrite the definition for KE to find vD and get vD =____________m/s.

From the literature we find sigma is about 7E-29 m2.

Rewriting the reaction rate equation as (nfuel squared/4) x vD x sigma and then rewriting it again so we can find nfuel ,

we have nfuel2/4= required reaction rate [i.e. reactions per m3per sec]/( vD x sigma) Multiplying both sides by 4 and taking the square root of both sides we find nfuel = ______ fuel nucleons per m3.

Congratulations, you just completed your second fusion fuel density calculation, and two weeks ago you couldn’t even define fusion.

Honors Homework and Sample Fuel Use Calculation

For tomorrow, complete all the calculations posted for you starting last Thursday. Also review the derivation of the elastic collision posted on Decemeber 4.

Here is a sample fuel use calculation

A power plant produces 500,000,000 watts of power. It produces power with an efficiency of 40%? How much deuterium and tritium (DT) fuel does it use in 1 hour?

It produces 500,000,000 J/s x 3600 s/hr = 1.8E12 J/hr. [ E12 means x10 to the 12th] To do this at 40 % efficiency means it uses about 1.8E12J/.4 = 4.5E12 of fuel energy per hour.

Each reaction produces 17.5 Mev which equals 17.5 x1.6 E-13(J/Mev)= 2.8E-12J

Therefore plant needs 4.5E12(J/hr) divided by 2.8E-12 J/reaction = 1.6E24 reactions per hour.

Each reaction uses 2 nuclei, one containing two nucleons and one containing three nucleons, for a total of 5 nucleons per reaction. This comes out to 5 x 1.67 kg per reaction. You are now on your own to calculate kg of fuel used per hour.

Mathematical Physics Unit 7 Schedule

Here are your schedule and work sheets for Two Dimensional Motion, Unit 7.

AND Remember a lab report can save your life.

CPMUnit72Dsched-07-8.doc

Worksheet12DMotionCPM.doc

Worksheet2forCPM2Dr1.doc

CPM2DWorkSht2B.doc

CPM2DWorksheet3.doc

Honors Energy Assignment

For Tuesday asnwer the following:

A typical fusion reaction produces 17.5 MeV per reaction and requires a deuteron with atomic mass 2 and a tritium nucleus with atomic mass 3. In other words an Avogadro's number of the reactions requires 5 grams of fuel.

How much fuel must be consumed per hour in a power plant that produces 1 billion watts at an efficiency of 33%? .

How many kg of this fuel would be consumed to produce the 1E20 J we estimated the US uses per year?

AP Rotational Solutions

Here is the link. This does not include text problem 55
APRotationalSlns0001.pdf

Mathematical Homework Momentum review

We will spend the next two days reviewing momentum, culminating in a quiz. 

FOR MONDAY, redo or do the momentum worksheet and problem sheet links are listed below.) Skip 8 and 9 on the problem sheet. The problem sheet has answers at the end, and  the link for the M-1 worksheet solutions  is posted below but no peaking until you have really tried on your own.

Use 

p =p'  i.e. m1v1+m2v2 = m1v1'+m2v2' 

and delta p = Jexternal = Fnet from external forces x  delta t  as needed for each problem. 

 For space module problem: Note that the explosion between parts of a system is internal not external. The force does not change the total momentum of the system but the two parts can have different momentums from each other after they are separated by the explosion.

Unit5HnrsProblemSheet.doc

MomentumWorksheetM.doc

MomentumWorksheetMsln.doc

Honors Unit 6A Energy production

In this unit we will determine the energy used by the US. We will then relatethis to the amount of fuel of various types that are required. We will then explore the reactions resulting in energy production particularly fusion and the required collisions between nuclei.

For Monday review all the fusion notes and the notes on heat and energy conversion.

Also do the following:
If 1 W = 1J/s and 1kW = 1000W then find:
how many J in 1 kW hour.

How many J do you use in 1 year if your house uses an average of 2 kW ( 31.5 million sec/yr)

If power is generated with 33% efficiency how many J of fuel energy is required?

if 1 eV = 1.6 x10-19 J how many eV in a kWh?

Energy for Honors Physics

We will spend the next few days in the enrichment mode, exploring particle collisions, energy production and the relationship between mass and energy.

To begin with try this out.

The energy matter contains is equivalent to the mass of the matter multiplied by the square of the speed of light. The average household uses something like 3 kW of electric power. Assuming that it uses this much power around the clock for a year ( 31.5 million seconds), How much matter will have to be converted to electrical energy to power this house. Take into account that the generation of electricity is about 35 % efficient. Turn in a decent calculation tomorrow  for some extra credit, but wait until we discuss it in class.

AP Fluids (Unit 7)

Here are the Schedule and Practice problems; the problem sheet;  a review sheet containing some questions and some notes; and some notes and a lab on Archimedes. This last item is what is meant by read lab on your schedule. 
APUnit7Fluidsched-07.doc

Unit7APProbSh-05R1.doc

ReviewSheetFluid06.doc

NotesonArchimedes.doc

Solutions to Honors nad Mathematical Energy and Work

Here is the link for the solutions


EnergyandWorkWorksheet1asln.doc

All Classes - Groups

Since groups are going to be such an importnat part of this class, I will allow you to have some say ( not the final say) in their composition. Therefore, please email me with your preferences. This is worth 5 extra credits for mathematical and honors students.

For AP students, this email is required and worth 3 homeworks.

Urgent: Group Meetings

Every group must have at least one meeting outside class hours for each subject ( unit). This goes for AP, Honors, and Mathematical.

AP must in addition meet at least once every two weeks no matter how long a unit lasts.

Every student must hand a brief report for each meeting covering : who was there, when it occurred, where it took place, and what was discussed and what work was done. Please keep this to about 2 sentences. It should take less than 5 minutes to write the report.

THESE ARE REQUIRED.

Since I cannot give Incompletes so easily, not meeting this requirement will result in losing a grade!!!!!

Homework and Outfolder

Check your outfolder every day. Many labs and assignments are left moldering in the outfolder.

If you distribute material from the outfolder, please return the t students rather than leave it on desks or tables where it can be damagged or lost.

Elastic Collisions

Here is the derivation of the equations for finding the final velocity after an elastic collision.

ElatCollderiv.doc

Momentum Lab

Here is a spreadsheet which has my take on the data and calculations for Honors Section 2. Note that the only big errors are for the last three trials. Looking at the data for these trials I see that cart A is consistently much slower then cart B. I suspect that cart A was in or very near the gate when cart B struck it. If this was so, the time in the gate would be longer than just the transit time associated with the initial and final velocities. This would give over long times and lower velocities for cart A which would probably explain the errors. If we have time sometime soon, we will rerun theses trials with a wider distance between the gates and see what happens.

CollisionLab.xls

AP Revised Notes on Torque

Here are notes on torque and Moment of Inertia. I hope we get to these soon.

NotesonTorquerev12-2-07.doc

Honors and Mathematical Worksheet solutions

Here are selected solutions to the worksheets from your classes last Monday and Tuesday. Use these to correct your work. There will be quizzes and tests on these concepts and problems.

WorkandEnergyWS-Asln.doc

PowerandEfficiencySlns.doc

Hnrunit6ProbShtsln.doc

AP Planet worksheet.

The Workbook contains a sheet called planet data form which is what you must use for the assignment. You may have to click on the the arrow in the extreme lower left to see it. When you do see it, you may see a bunch of ###s in the mass column. Just highlight all those cells and go to format then  cells then number and then choose scientific and 2 decimal places. You will see the sun has a mass of 1.99 E30. 

Note that the mass column labeled earth masses means exactly that. The sun has a mass of 333,000 earths NOT 333,000 kg. The earth has a mass of 5.98 E24 kg. Yes, the sun does have considerably more mass than a small freight train.

Please do not tell me that you think the period of the earth's rotation is trillions of years.

Honors and Mathematical Classes Momentum Labs

Make sure you have your momentum Labs and data with you this week. We will be going over it in class and in the computer lab this week. Read the blog posts on this lab; there are three posts.

Honors and Mathematics Weekend Homework

For this weekend , go over the sheets you did on Monday and Tuesday and make sure you have the correct method of solution. There will be a brief quiz on a couple of these Monday.

Most of what you need is written as introductions to the two worksheets. The problem sheet is a little tougher, but we went over the key problems in class. Do read the all the notes on work and energy posted onthe blog with the Unit 6 schedules on November 21.

Here are links:
WorkandEnergyWS-A.doc

PowerandEfficiencyWorksheet.doc

Hnrunit6ProblemSheet.doc

Conservation of Mechanical Energy Lab

For this lab, you obviously should compare the change in PE, from the point where the cylinder is released to the bottom of tis arc, with the gain in KE from the release point to the bottom. Since KE = 0 at the release point, the change in KE is simply the KE at the bottom. Therefore you should be finding out if Mg (hrelease- h bottom) = Mv(at bottom)squared/2.

We find v from diameter/t because the light is blocked for the time it takes the cylinder to travel one diameter as it passes through the photo gate. However, this is not quite accurate. The light is not completely blocked until the cylinder reaches the far edge of the bulb in the photogate head, and light starts to leak through once the back edge of the cylinder passes the near edge of the bulb. So in effect, the cylinder only has to travel its diameter - the bulb diameter, during the time the light is blocked. Even this is not quite right since the hole the light enters is much smaller than the bulb, so maybe the correct distance is cylinder diameter- hole diameter or something between the two. Think about it and you might use it to explain why your first calculation of KE may be greater than the initial PE.

Planets Work Sheet for AP

Here is the link. Use the sheet labeled Planet Data Form

PlanetsWS.xls

Correction to Honors and mathematical Unit 6 practice problem

The answer to the Unit 6 Practice problem 1 , how much fat you lose climbing the Empire State Building should be .062.

AP Momentum Lab of 11/20

Yes it is formal. You should include enough information to determine if the total momentum was conserved; i.e. ( treating momentum as a vector) see if the total momentum of the two carts is the same before and after each collisions. You should determine the percent error. You should also check to see if KE was conserved, i.e. was total KE the same before and after. Read the two posts on the blog for my Honors and Mathematical classes for the momentum lab for further details

AP Unit 6 Schedule Correction

I did it again somehow; another typo. For Tuesday night do Chapt 7 prob 21-24,26. For Wednesday do Prob sheet 1-6

Momentum Lab Take 2

For your lab reports percent error can be positive or negative depending on whether the final momentum is less than ( negative error) or more than( positive error) the original momentum.

For runs where both carts were originally moving, the percent error can appear to be unreasonably large. This is because to find the original momentum we add one large number positive number to a large negative number and finding relatively small difference between the momentum to the window and the momentum to the door. A small percentage error in the large numbers can cause a large precentage error in the relatively small difference between the doorward and windoward momentums . Then we do the same to find the final momentum and compare the two. If we take the initial total momentum ( total meaning taking windoward as positive and dorrward as negative for example) minus the final total momentum and divide by the intial total and multiply by 100we can get a very large percent error, because we are dividng by the difference between two large but similar numbers. In order to get a real sense of the percent error, try taking the final total from the initial total and then dividing by the sum of the magnitudes of the initial doorward and initial windowward momentums, (i.e treating both windoward and doorward momentum as positive in the denominator). Of course multiply by 100 to get the error in percent.

AP Rotational Motion and Gravity

Here are the links you/ve been waiting for. You didn't think I would abandon you over the holiday weekend, did you?

Do enjoy your holiday, remember to be thankful for all the good things you have.

APUnit6sched07.doc
Some useful notes on the subject. Do read them:

RotationalMotionDefnsetc.doc

NotesonTorque.doc
planetsorSatellitesinOrbit.doc
Sheets you need for homework
APUnit6ProblemSheet.doc
I think I called these WS R-1 and R-2 on your schedule. Whatever I called them, here they are:
ProblemSheetR-1.doc
ProblemSheetR-2.doc

Mathematical Honors Unit 6 Schedules and WorkSheet

Here are new links. Make sure you read the notes on Work and Energy
All:
NotesWorkandEnergyR3.doc

EnergyandWorkWorksheet1a.doc

Honors:

HonorsUnit6EWsch-07.doc

Mathematical:

CPMUnit6EWsch-07.doc

Momentum Lab using Carts

For the Momentum lab, we gathered data from several collisions. Ideally the total momentum of the two carts ( p1 and p2 added together) should be the same before and after the collsision.

For this lab, you should describe the procedure, carefully outlining which series of trials had M1 (or MA) greater than M2 (or MB); which series had M2 greater than M1 and which series had M2 as well as M1 moving before the collision.

You should have your original data tables. Use the time data to ind t1, t1', t2, and t2'. Be careul remember which times are from before the collsion and which are after. Remember to subtract where necessary and that t2 did not exist for many cases and t1' didn't exist for some.

For results discuss which cart moved which way after the collsions. Then find your v1,v1', v2 and v2' keeping track of which are positive ( toward the windows, as we did it) and which negative. Do the math for each trial to see if

m1v1 + m2v2=m1v1'+m2v2'

for each case. Find the percent error and see if momentum was approximately conserved. Discuss why differences may have occurred.

URGENT TO ALL

There has been a failure on the hosting site I use for documents. Please refer to my oncourse website homework events. There are important Unit 5 schedule revisions , Unit 5 worksheets posted 11/12 on the calendar and an AP derivation posted on 11/13

Honors and Mathematical Homework

You do not have to do Problem 11 on the Problem Sheet. We will cover this later

DuPont Science Essay Contest

There is a science essay contest sponsored by Du Pont with monetary rewards and a possible trip to NASA and Disney World.

Contact me if you are interested.

Momentum Worksheet for Honors and CPM

Here is the link to the momentum worksheet and the problem sheet. Both CPM and Honors should do these as described in your schedules. We will go over this in class

MomentumWorksheetM.doc

Unit5HnrsProblemSheet.doc

Rev 1 AP Unit 5 Momentum Work and Problem Sheets

Here are the links

Unit5Worksheet1.doc


Unit5Worksheet2.doc

Unit5ProblemSheet.doc
Unit5extraproblems.doc

Mathematical Important Homework and Test results

While most of you did improve on your first force test score, the test results were very disappointing except in 4 instances. Many of you still fail to grasp the basic concepts of force. You must realize that we are studying the real world, not some arbitrary nonesense. Physics explains what you see and feel every day. It will match your experiences if you observe them and interpret them intelligently.

For example, you all know that the force gravity exerts on an object depends on the mass of the object. The force of gravity on a car is not the same as that on a mouse. IT IS NOT 10! it IS Mass x 10N/kg.

Objects on the ground or on table tops or other surfaces do not fall through the ground, table top, or other surface. In addition to force of gravity, these objects experience a normal force upward and opposing gravity. In the absence of any other vertical forces this normal force is equal to and opposite gravity. These two forces together than add to zero force net perpendicular to the surface.

Gravity does not make things accelerate horizontally.

You know things sliding on ramps do not acclerate at the same rate falling objects do, and that the steeper the ramp the faster they accelerate. This is partly because of friction, but mostly because the force pulling down the ramp is only a component of gravity not the whole Mx10. You know it is easier to walk up a ramp then to climb a vertical ladder. This is why.

Some of you are still in the mode of taking whatever numbers are in front of you and putting them into the simplest equation at hand. For example, several students tried to find the force of tension in the rope between two masses on a horizontal surface by subtracting one mass from the other. Force cannot ever = Mass1 - Mass2 period. Force is not the same kind of quantity as mass. The correct answer is found by applying the fact that the rope is causing the second mass to accelerate. This relationship, F on the object =Mass of object x acceleration of object, is a keystone of classical physics, and something we have been studying through experiments, reports, demonstrations, class problems, and discussions for three weeks.

It seems that your observing demonstrations and experiments and reporting your results; my writing on the board; and our discussing things in class, is not sufficent for you to retain some basic facts Therefore you will turn in as homework the following.

Write clearly ten times each

1)Acceleration in a direction = the sum of the force components in that direction divided by the mass being accelerated

2) The component of a force in a direction is equal to the force x the cos of the angle between the force and the component

3) Force of gravity on an object (N) = Mass of object(kg) x 10 N/kg

4) The unknown force on an object in a direction = Mass of object x acceleration of the object in that direction - all the known force components in that direction, with the signs of the force components indicating whether they are positive or negative in that direction ( - means opposite of positive direction)

5) if the component is in the same direction as the force, then the component = the force


This is due Monday, and failure to turn it in will reduce your quarter grade by 5 points, spread the word.

There will be a retest on Tuesday. Note taking is now required and will be reviewed and graded for the forseeable future. Bring the equipment you need to take notes every day.

Unit 5 Schedules for All

Just so you don't have to suffer from withdrawal symptoms from your favorite activity, here are you Unit 5 schedules. In additon, Mathematical students can think of a physics question or topic for discussion

APUnit5MomentumSched07.doc

CPMUnit5MomentumSched07-8.doc

HonorsUnit5MomentumSched07-8.doc

Vector Lab for all classes

The vector lab required you to make two drawings one adding vector A to vector B and comparing the result, vector B+A, to vector C. This result points from the origin (the knot) to the end of the vector A that you stuck onto to vector B It should be a vector as long as C ( i.e. the same magnitude of force) pointed in the opposite direction, but don't fake it.

The next drawing required you to add vector B to vector A and then add vector C to the end of the vector B that you just placed on the end of vector A.

Note that vectors do not add as simple numbers. While vector A + vector B may add to - vector C it does not mean that magnitude of A + magnitude of B equal magnitude of C.

In your drawings you may think of magnitude as length although the length stands for force strength.

Honors Labs

Tomorrow is the last day for you to get your first quarter labs to me, including the one with two weights providing a net force.

AP Consrvation of Energy Lab with Ramps

I will need a complete description of what you did to evaluate your labs. Therefore it is a formal writeup this time. I'll make it due Wednesday to help reduce the pain.

Honors Fnet = Ma? with 2 weights Lab

Most of the period 2 labs and some of the period 4 labs missed the point again. You were supposed to find the ideal Fnet from M2 x 9.8 - M1 x 9.8 and then compare it with Mtotal x a measured to see if Fnet = Ma. Mtotal = total cart mass plus M1 and M2.

Any difference can be ascribed to friction.

A similar approach to the first a=F/M lab is described in posts of 10/21 and 10/24. Read them now, especially if you still have an a=F?M lab to submit or resubmit.

AP Lab Resubmittals

The resubmittals are very disappointing in many cases. Most of you did not fix the major problems with your lab and did not seem to even bother reading the extensive blog posts on the a=F/M lab(see posts on 10/21 and 10/24.) In the future, if you resubmit a lab with the same major errors, ignoring the comments I write on your paper AND on this blog, I will deduct points from your existing grade. I have enough to do without wasting time seeing the same errors a second or third time. How you can say your lab demonstrated F=Ma without your even knowing what F is, continues to amaze me, as does your thinking that a 100g mass produced 100 N of force. In future quarters, resubmittals will only be accepted where I specifically ask for them. Failure to resubmit will result in the original grade being entered in your quarter grade. Failure to respond to a see me will result in a ZERO for the lab.

If you do not know what you are doing, see or email me BEFORE submitting a faulty lab report.

To Parents and other HAC users

I have now posted most assessments for all classes on line and they should be accessible to the HAC. Do not pay any attention to the student averages. Eschool cannot calculate grades the way I do, adjusting for a students particular learning styles and abilities. If what you see causes any concern, please email me.

One area that you may want to pay particular attention to is the lab assessments. Please note that low grades on first quarter labs can be raised by resubmittals, but please know what was wrong and how to correct it before you create your resubmittal and ask me to grade it. While I am flexible about many things, grades will include a signicant lab component since about 20% of of the course credit is based on it being a lab course.

Grades of "other" mean that while the item was received, for one reason or another I did not award a grade for it. Students must see me about these items or they will become zeros at marking time.

The purpose of attending school is to learn, not to be judged, and a grading system is at its best when it encourages learning. Please use the information available to you help your student learn.

AP Unit 3 Retest

All students who received a score of less than 75 on the the Unit 3 test may take a retest on Monday or Tuesday outside of class hours. You must email me if you plan to take it.

If you take the test on Tuesday, it must be before 6th period. It is advisable that ytou get help before taking the test. The maximum grade you can receive will be equivlanet to having scored a 75 ( equivalent to a B-) on the orignal.

AP Unit 4 Problem Sheet

Just in time, I hope

unit4ProblemSheet.doc

AP proof of Pulley system a of center of mass=F/m

Here is a link to a brief proof that when you include all the forces acting on a weight / pulley system, the acceleration of the center of mass = Fnet on system/ mass of the system

Atwoodcomprf.doc

Mathematical Worksheets

Sorry for the delay . Here they are
Unit_4CPMWS-1.doc

Unit4CPMWS-2.doc

Honors and Mathematical Reading

If I were you I would refreah my memory on gravitational and electrical forces. You never know when there will be a reading quiz.

Honors Period 4 Force Lab

Imagine how pleased I was to see your out folder still full of the lab sheets for your force lab. It made me so glad I interrupted what I was doing yesterday to make sure they were available for you.

Please spare me experiencing the same pleasure tomorrow.

Study Groups

For Honors classes for this quarter, each group must meet at least once outside of school hours ( it can be at school). Every member of the group must turn ina report for each meeti ng. The report should be brief covering where, when, who was there, and what was covered ( in one or two sentences. )

If you fail to submit at least one report you will receive an incomplete for this quarter.

For the rest of the year you must meet and report once per unit. At least half the meetings should be outside school hours the remainder can be during lunch or study halls.

Notes on Work and Energy

Here are some good notes on Energy and Work. Read them they will make you smart ( as if that were possible).


NotesWorkandEnergyR3.doc

AP Energy Conservation Lab

The energy conservation lab, where I hope you demonstrated that delta KE = - delta, PE requires a formal write up . The write up must follow the outline in the course guide and your discussion and conclusion should convince me that you understand the principle involved and if, and how, it was demonstrated. It should also contain information such as the diameter of the object, how you measured it, how you calculated its velocity, and exactly how it felt about being treated the way it was ( oops skip the last part, this is physics not psych). Your reports are due Wednesday.

AP Unit 4 Worksheets

Just so you can have an excuse for not going out and carousing with your delinquent friends,which I know you really don't want to do, here are the worksheets:

Unit4worksheet1.doc

Unit4worksheet2.doc

Honors and Mathematical

All homework that has not been handed in and recorded for a unit, must be turned in on the testing day for that unit for you to receive credit. I will hold Unit3 open until Monday since some of you forgot this.

Mathematical Unit 4 Forces in 2D Schedule

Worth waiting for .... maybe.

CPMunit42Dforcesched-07-8.doc

Keep alert for the worksheets, which will be posted soon.

By the way, some pretty good work by many of you on the a=F/M lab.

Honors Unit 4 Revised Schedule

Here is a schedule with corrections to the equations. Just remember: typos are my most important product

Honorsunit42Dforcesched-07-8r1.doc

Honors Unit 4 Schedule and Work Sheets

Here is the schedule for Unit 4 where we deal with forces in more than one dimension

Honorsunit42Dforcesched-07-8.doc

Unit4HnrWS-2.doc

Unit_4HnrWS-1.doc

Mathematical a=F/M lab

Read my comments on Honors a=F/M lab and save yourselves some trouble.

Honors a=F/M Labs

The period 2 lab reports continue to range from amusing to exasperating. At least you all plotted a on the vertical axis and something to do with mass on the horizontal axis. You should have plotted a vs 1/mass. Many of you plotted a vs mass instead of a vs 1/mass. Some of you plotted the 1/masses at equal intervals using , or rather misusing, EXCEL. You must use the scatter plot format to plot data at the proper locations on the horizontal axis. (EXCEL was designed for business purposes, not real calculations so their normal graphs destroy useful data).

Almost no one said what the space between the gates was; how many cm was the delta x in the calculation of a. Information like this belongs in your report

In many instances there were serious errors in calculating a. Some of you forgot to use the correct band length. Some of you rounded so carelessly your graphs came out lumpy instead of linear and your slopes became inaccurate. Someone used cm/s for v but used meters for for delta x so that a came out a factor of 100 high. This extremely high value was then used in the lab report as if nothing was wrong with it. Very few of you divided the kgcm/s2 by 100 to get kg m/s2 which is what you need if you are going to compare the slope to the force in Newtons [ 1N = 1 kg m/s2].

Nearly all of you said confidently that the slope was the force (including those who plotted graphs of a vs mass for which the slope was a/m instead of ma). However only three of you bothered to actually calculate the slope and compare it with the force, which is the only way you could demonstrate that slope which is a/(1/mass) =a x m actually does = F

It is not clear that most of you realize what the force causing the acceleration was in the two runs, so that you would know with what you should compare the slopes once you have calculated them. In fact only two of you indicated that you knew the force causing the acceleration was equal to the mass of the hanging weight x 9.8 N/kg. This comes to .98 N for a 100g hanging weight, .49 N for 50 g hanging weight, and 1.96 for a 200g hanging weight. Fix this. Calculate slopes, compare them with F and show the calculation and discuss the results and the reasons for them in your conclusion. You need to think and then demonstrate that you have thought, learned, and understood.

The last question about why the line of best fit intersects the horizontal axis at some point to the right of the origin elicited a few correct explanations. Think about the relation between a and 1/mass. If F = something greater than zero what does 1/mass have to be for a to equal zero? If a = 0 and 1/mass was not zero (i.e. the mass of the system was not infinite) what does that say about the net force on the system? If the net force is zero when the force of gravity was applying a force on the system what other force is probably present? 10 additional points of credit on the lab if you can identify it and calculate it for at least one run ( not trial). Again show the calculations and discuss the results and the reasons for them in your conclusion. You need to think and then demonstrate that you have thought, learned, and understood.

Your error analysis should not be a laundry list of what might have gone wrong but did not. It should just address the things that actually did or probably did happen. For example, don't say you might have had the timer on the wrong setting when you have only a 5 % error.

Discussions and conclusions are not the place to describe the procedure. Also they are not the place for a review of how you feel about the lab. You can't just say you learned a lot. You must show calculations that justify your conclusions. You must say exactly what you learned, probably expressing it in equations at some point.

I am hopeful that period 4 labs are better since they were warned before handing them in. We shall soon know.

To Parents of Honors Students

Approximate grades as of 10/17 can be found under the Teacher Defined 2 assessment. The other classes should be up in a day or two. While the individual assessments are valid, the student averages are meaningless because the system cannot match the way I do my weightings to address the different strengths of students.

These grades can change pretty drastically as new material is turned in; new tests are taken, and new material becomes due.

One important category where you may influence your childs performance is labs , and I will try to keep the labs fairly up to date. Please encourage your student to turn in labs on time and to think about what their purpose was and how to learn from them while writing the reports instead of getting them out in the shortest possible time with the least amount of effort.

AP Extra Problems for Unit 3 errors

Unfortunately I uploaded the wrong version of the extra problems. With the help of Sydney Orthmann I have uncovered a couple of errors and there may be more.

The errors so far are the tension in problem 7 should be 4 N ( you should have found the acceleration = 2m/s2) ; the answers c and d showing for problem 13 belong to problem 14 and the a for problem 14 is -6.6 m/s2. I will try to locate the correct version, but in the mean time stick with this one and I'll try to get through all the odd problems to check the answers by tomorrow.

AP Homework

There has been some ambiguity about your recent assignments. I will now clear that up. By tomorrow, i. e., Tuesday10/23, you should have completed the odd numbered extra problems and the practice problems. This will leave you Tuesday evening to study for the incredibly difficult test I am preparing for you. In fact, you probably should cut all your other classes just to study for it.

Well maybe not.

AP Unit 4 Work and EnergySchedule

Here is the link to the AP Unit 4 Schedule. This is a first draft and there may be changes.

APunit4sched-07-8.doc

AP a=F/M Lab Reports

Your lab reports continue to range from amusing to exasperating. Some of you persist in plotting the wrong variables on the vertical and horizontal axis. Avs B means A on the vertical, B on the horizontal. You should have plotted a vs 1/mass. If you did the reverse, you must fix this. Nearly all of you said confidently that the slope was the force (including those who plotted 1/mass vs a for which the slope is 1/force). However only one of you bothered to actually calculate the slope and compare it with the force, which is the only way you could demonstrate that a =F/m.

It is not clear that most of you realize what the force causing the acceleration was in the two runs, so that you know with what you should compare the slopes once you have calculated them. Fix this. Calculate slopes, compare them with F and show the calculation and discuss the results and the reasons for them in your conclusion. You need to think and then demonstrate that you have thought, learned, and understood.

The last question about why the line of best fit intersects the horizontal axis at some point to the right of the origin elicited many very interesting, but few correct explanations. Think about the relation between a and 1/mass. If F = something greater than zero what does 1/mass have to be for a to equal zero? If a = 0 and 1/mass was not zero (i.e. the mass of the system was not infinite) what does that say about the net force on the system? If the net force is zero when the force of gravity was applying a force on the system what other force is probably present? 10 additional points of credit on the lab if you can identify it and calculate it for at least one run ( not trial). Again show the calculations and discuss the results and the reasons for them in your conclusion. You need to think and then demonstrate that you have thought, learned, and understood.

If you have not turned this lab in, or any other outstanding lab or resubmittal , do so by the Wednesday. All late labs do lose points

Honors and Mathematical Revised Sheet F-1

Here is a minor revision to Sheet F-1. It changes what is applying the force and what is feeling the force in Question 2.

PhysicsWorksheetF-1r1.doc

Honors and Mathematical Physics Homework

Your assignment for the weekend is now to do the Worksheet F-1, posted a few days ago

AP New Homework - Forces Extra Problems

Your Assignemnt for the Weekend is now to do the odd numbered problems from the extra problems posted below:


unit_3_extraproblems.doc

Honors and Mathematical Worksheet F-1

Here is the link to to Worksheet F-1

PhysicsWorksheetF-1.doc

Mathematical Physics Worksheet F-2

Here is worksheet F-2

WorksheetF-2CPM.doc

Worksheeet F-2 for Honors Physics

Here it is WorksheetF-2Hnr.doc

AP Unit 3 Forces Worksheets

Here are the Worksheets and problem Sheet for Unit 3

Unit_3_Worksheet_1.doc

Unit_3_Worksheet_2r1.doc

Unit3problemsheet.doc

AP a=F/M Lab

I am much too kind, a fault I am working to amend. We'll make this lab informal ( i.e. a minilab) as well, but the next one will be a formal one so don't even ask me about it.

Physics Club - Finally a club post

Item 1 The best way to enjoy the club is to be active. Volunteer to make a presentation on your favorite subject. Have something you're dying to learn about? Research the subject and then you can share your new knowledge with your buddies. If you need any help, I will be glad to provide it. Also don't forget feeding this army of physics enthusiasts is another way to participate. Sign up for bagel provider.

Item 2 Physics team members, we will meet briefly, Wednesday at 7:15 in 506 to review the activites and try to set up a meeting schedule. Email me whether or not you can make it. And best of all, its not too late to join.

Mathematical Physics Lab

Have your graphs form the a=F/m? lab ready by Tuesday. We will discuss them in class

Honors Unit 2 Test 2

Students who achieved a score of less than 77 on Unit 2 Test can take test 2 on Tuesday, subject to the following:
must have completed all Unit 2 Homework and attended a help session by before class Tuesday
You must tell me when you plan to take the test.

Test 2 will be given outside class hours.

Honors Section1 ( Period 2) Unit 2 Test

Please turn in your Unit 2 Tests on Monday. They will be returned to you by Tuesday morning

To parents: Interim Grades Take 2

I posted interim grades as letter grades under assessment TD1. I have now been told that the system cannot transfer letter grades for assessments to your HAC. They are trying to cure this. If they don't succeed I will post numerical values under TD1.

Apparently, even though my comments, the more valuable part of an IPR, show on my screen. They will not transfer to HAC.

If there are any comments that require your attention I will forward them by email, provided you have sent an email to me so I have your address.

Honors Section 2 Period 4

Please have your parents send me an email so I will have their addresses. The address line should include the name so I don't have to hunt for it. (10 points of extra credit for doing this.)

Honors Unit 3 ( Forces) Schedule

Here is the schedule for our new unit on forces. The book assumes you are using vectors and 2 dimensions. We will start doing 1 dimension ( one direction) only, so don't worry about those few places where 2 dimensions are discussed.

Honorsunit3Forcessched-07-8.doc

Interim Grades

I posted interim comments on the Interim grade forms so they should be where you would normally find them on the interim grade sheets.

Because I attempted to develop a more comprehensive assessment of your performance in the class ( read that as looking for a way to allow you to turn in those missing labs and to give you a second test score to make up for the first test that you bombed) I had to post your interim grades in the assessment area of the Home Access Center under the title TD1. I hope they are there.

These grades are based on pretty early indications and they are neither reason to be discouraged nor to rest on one's accomplishments. I hope they do act as a wake up call to the delinquent amongst you.

Mathematical Physics Unit 3 Forces Schedule

Here is the schedule for Unit 3 which covers forces and the accelerations they cause.

CPMunit3Forcessched-07-8.doc

AP Unit 3 Forces Schedule

Better late than never

APunit3sched07-8.doc

NJIT Open House

The New Jersey Institute of Technology open house will be held Sunday October 28. For more information see the NJIT web site: http://www.njit.edu/admissions/visit/undergradopenhouses.php

Chance to study medicine during the summer

There is a 10 day summer program for those who would be interested in pursuing career in medicine. It requires a GPA of 3.7 out of 4. It will be held in various major cities. The cost is substantial, but scholarships are available. Those students who did attend in the past enjoyed it and thought it worthwhile

If you are interested, see me.

Honors Computer Labs

We will be using the computer lab on Thursday morning( Honors Sect 1 period 1) and next Monday ( Honors Sect 2 period 4) to practice entering data, calculating quantities, and creating graphs on a spreadsheet.

Make sure you have data tables from either the moving cart or free fall labs with you. Both is betterPublish Post

Lab Reports from Mathematical Class

1) The free fall lab report must be a formal report. You should discuss relationship between position graph and velocity graph, and the realtionship be the velocity graph and acceleration. Think about what the slope of a graph means with regard to change and time. See a previous post for more info.

2) Many of your lab reports for the moving cart followed no format at all. IF so your grade is conditional on your turning a correctly written lab report in the formal format for the Fall Lab. Otherwise you will lose 15 points from your current grade for the cart lab.

All students homework

Having decided that there was not already enouigh misery in the world, I have decided to add to both mine and yours. Please turn in all unentered ( i.e. those with no eps or RCs or checks on them) homework tomorrow. Please pass the word to your fellow students and to those other guys you hang out with who are in my classes.

AP Vector Labs

I was very disappointed in one particular aspect of the performance on the vector lab. Despite explicit instructions to find the vector sum of A+B graphically and also find A+B+C graphically only a handfull of reports showed both operations. They should be done on separate sheets.

The purpose of the lab was to provide exercises that would allow you to understand the validity of the head to tail method and more importantly get a hands on intuitive feel for adding vectors other than simple displacements. Please be more conscientious in the future.

Honors and Mathematical Freefall labs

For your free fall labs , you should plot the cumulative distance vs time, the velocity vs time, and the acceleration vs time. You should discuss the shape of your curves and whether or not they met your expectations.

Find the acceleration from your data and from your velocity graph (think about how you find acceleration from the velocity graph). Does think acceleration match your expectations? Is it about g?

This is an informal or minilab so follow the guidance in your course guide.

Honors Graphing Data

Here is the link for the velocity graph and data table for your assignment.

Please plot the position time. Remember that the total change in position is the total area between the velocity curve and the v=0 axis.

Think about what you should do when the curve is beneath the axis - does the area in this region represent a negative change in position?

studentdvacurves.xls

Mathematical Physics Revised Schedule for Unit 2

Here is the link for the revised, and much easier to live with Unit 2 Schedule.

CPMUnit2Sched07-8r2.doc

AP Physics Vector Lab

For your vector lab, write a mini lab (informal lab). The purpose of the lab is to determine if the head to tail graphical method of vector addition works. To do this use the fact that if an object, in this case the knot at the junction of the strings ( the middle of the "Y" ), is not accelerating, the sum of the forces on it must be zero. Therefore, the vector sum of the three forces must be zero (for each force the direction is given by its section of string, magnitude given by its scale) .

Draw A + B and see what its resultant equals Then, on a separate sheet, draw A+B+C and see what its resultant equals. Make sure that when you, for example, add vector B to vector A's head, you keep B's direction and magnitude constant, etc.

Explain if the resultants are what you expected based on what you know about the sum of the forces, and if not , why not ( error analysis).

While you are at it, make sure your discussion answers all the questions on the lab sheet.

Honors Physics Graphs

For Monday, please have your position (column B) vs time and velocity (Column D) vs time graphs completed. Remember A vs B means that the A axis is the vertical axis. Also keep in mind that if your timer was set for 1/60 of a second and you were to choose every third dot as a data point, your time interval would be 3/60 = 1/20th of a second. If you used every fourth point your time interval is 1/15 sec; etc. Choose scales so that graph will nearly fill the page.

When you draw the line on your graphs, choose a smooth curve that follows the trend of the data, NOT a jagged line that connects the dots. For velocity , see if a straight line follows the trend of the data pretty well.

Think about how you would use a tangent line to find the slope of the position curve.

Put the words " read on the blog" on the top of your position graph for 5 extra credit points.

Mathematical Physics Graphs

Please have your position ( column B) vs time and velocity ( column D) vs time graphs from Friday's lab ready for Monday. We will use them for the basis of our discussions Monday. Remember then when you graph A vs B the A axis is the vertical axis. Do Not graph delta V Column E or acceleration (Column F) yet.

If you had the timer set at 10 hz (as you should have), your time interval was 1/10 = .1 seconds. Also, choose scales so that graphs will nearly fill the page. If the page is 30 boxes wide let each time interval ( each .1 seconds) be two boxes. If your maximum distance is 70 cm and the page is 80 boxes high, let each cm be one box.

Put the words " read on the blog" on on the top of your position graph for 5 extra credit points.

Honors Unit 2 Schedule

here is the schedule for Unit 2 1 D Motion
HonUnit2Sched07-8r1.doc

Make sure you keep up with the Homework.

Mathematical Unit 2 Schedule

Here is the schedule for the new unit:

CPMUnit2Sched07-8r1.doc

AP Unit 2 Schedule

Sorry folks but I could not get the schedule into the last post so here it is now:

APunit2sched07-8.doc

AP Unit 2 2 D motion

Here are schedule and materials for Unit 2 2D Motion, but to keep checking for revisions, and perhaps even solutions to some problems.

Relmotionproblemsfor2D.doc

Unit_2_problem_sheet.doc

Unit_2_worksheet_1.doc

Unit_2_Worksheet_2_.doc

Unit_2_Worksheet_3.doc

Honors link to Fusion reading

Here is a link to the complete file for the Hoffman Fusion paper. The hard copy you received in class does not include the last several pages. This uploaded version runs 17 pages. Check your schedule to see which you are required to read, but reading the entire paper is not a bad idea.

HoffmanonFusion.doc

Honors Unit 1 Review Worksheet

Here is a link to the Unit 1 Review Worksheet that includes the second page.

HnrsUnit1RevWorksh.doc

Heat and Energy Conversion

Here is a link to some notes on Heat and Energy Conversion I would like Honors and Mathematical classes to read. I believe most honors students have these already. Thye tie into the controlled fusion power theme.

For mathematical class students, these notes provide a brief introduction into energy and how we use heat to produce electricity.

HeatandEnergyConversion.doc

Seniors seeking college recs

If you are going to ask me for a recommendation ( clearly you like to live dangerously; don't really want to get into a college: or are so overconfident that you think anything I write won't keep them from admitting you), now is the time to send me an email to that effect. I, in turn, will send you an email telling you what I need from you. If you are going early decision, etc. or applying to a school with rolling admissions you must get the material to me by October 5.

Mathematical Physics Unit 1 Revision

Here is a link to the revised schedule for Unit 1 . It corrects some errors about what is to be covered during this Unit.

CPMUnit1Sched07-8R1.doc

Mathematical Physics Math Review Sheet

Here is the link to the review sheet you are assigned to read over the weekend. Of course, it wouldn't be a bad idea to read it tonight.

MathRevForMathPhysics.doc

Honors Physics Math Review Sheet revision

Here is the link to a revised math review sheet. The old one had a few typos. The one that mattered most was on page 3 it should have show m =(m/s) x s; NOT m= mx(m/s)

MathRevHonPhys06-07.doc

Lab Safety Sheets and Course Guide Signature Sheets

Folks,

Lab safety sheets were in the out folders for each class. Have them signed and returned no later than class on Monday.

Course Guide signature sheets should be placed in the in folder for your class by class Friday.

Honors Assignment

In addition ot what is on the Unit Schedule, please summarize our experiment on circular motion. Cover what you did, what forces your felt, and your conclusion about the direction of the forces on you. Turn this in to the in folder on Friday.

Important earlier posts

Folks, go check my posts from this summer about scholarships and outside opportunities for learning science. Also make sure you see posted Honors and AP Unit schedules

Mathematical Physics Schedule is Coming

Folks in my mathematical physics class, please don't feel left out. I need to consult with Mr. Florance before I create your unit 1 schedule. I know how upset you are because you do not having mounds of homework yet so Iwill do my best to supply you with all the work you've been hoping for soon.

AP Physics Unit 1 Math Worksheet

Here is Unit 1 WS-1, a set of math problems you have been asssigned. Also, check out the post for Honors math review. Their math review sheet (not the worksheet) may also be of help to you.

unit1mathreview.doc

Honors Physics math review and math work sheets

Here are math review sheets and worksheets you will need:

mathHnrwkshtRNCR4.doc

MathRevHonPhys06-07.doc

Welcome

Welcome to my blog. This will be a key method for communication with my 2007-8 students. Anything that will apply to groups of students, classes as a whole, etc. will probably be posted here. For more individual communication, email works best.

If you send an email to my school email address by Friday, telling me you read the blog you will receive 5 points of extra credit.

Also, see earlier posts for information on physics and specifically for Unit1 Honors and AP schedules.

Honors Unit 1 Schedule

Here is the schedule for Honors Unit 1

HonorsUnit_1_Sched07-8.doc

AP Unit 1 Schedule

Here is the schedule for the first AP Unit

APUnit1Sched07-8.doc

Website

My website on the oncourse server is up and running (well more like walking). The URL is http://www.oncoursesystems.com/school/view_webpage.asp?id=308508

The link should appear in the directory of online resources on the Bernards BOE homepage as well soon.

Extra Curricular Physics Programs

Here are some opportunities for extracurricular physics activities into which you should be looking.

Extracurrphysicsprog.doc

Dr Cherdack has Website - almost

I will soon have a web site to which you can gain access from the Bernards BOE site. It should be up and running in a week or two; as soon as the IT department gets a chance to review it and enter the URL link. [ If you were paying atttention you will have noticed that I neither used access as a verb - it isn't one; nor did I end a phrase with a preposition. You can learn more than physics around here, although learning just physics is good enough.]

Scholarships

There are lots of scholarships available for a wide range of students. Many of them require that you show particular skill or interests by participating in programs, creating projects, performing public service, or a combination of these. You should be looking these opportunities over by now and deciding which of them are possibilites. The Siemens scholarship is an excellent example, and some of you should have given it serious thought. You guidance counselor is a good source of information on all this and she can point out websites and other resources for you to use to identify the scholarships which mught interest you.

Credit for Honors review Packet

I am still looking for the name of the person who submitted a review packet on blue lined paper.

It might make a difference to his or her grade. If you read this, please pass it on.

Back from vacation

Folks,

I am back from a vacation to the Pacific Coast and Sierras in California. I will try to respond to emails by next Monday.

Physics for 2007-08

Please let me know ( via my Ridge email) if you wanted to take Honors research - topics in physics , in 2007-08 and you could not fit it in your schedule or had to drop it because it was not offered.

Also, note that the opportunity for individual research in physics may still exist. It would be a separate credited course with hours arranged between instructor and student. I believe the number of credits can be varied depending on the level of effort the student and teacher agree upon. Hours outside of the normal school day are possible and they can vary from week to week. Let me know if you are interested in this ( via my Ridge email) .

Obviously, only a few of you will read this so please ask anyone else you know who took physics last year to check the blog.

Thanks

Honors Exam

Please do not forget light. I did not put it in the rview packet because it was just completed. Please know some basic facts about frequency, refraction, and reflection. You do not have to know how lenses work.

Honors 8 th period kinematics project

To Eric Kate, Megan and Zac,

I am still awaiting a corrected calculation poster reflecting a more accurate delta h measurement.

Third Period Honors

I am missing much work from members of this class.

Great Adventure Labs from Cathy F., Kristi Fogel, Eric, KC and Frances.

Projects and/or written project reports from Rachel, Ian ( telescope but not a word on why it works) Kristi, Jen, Zach, Frances, and Reid.

Air Resonance Lab from Rachel, Cathy, Kristi, Erci, Ian, Christina, Amanda P., Frances, Jon and Reid.

Snell's law Lab from Rachel, Cathy, Kristi, Erci, Brett, Ian, Frances, Jon and Reid.

Some of this may be errors in record keeping or reports placed in the wrong folder, but I must hear from you by Wednesday with your material or your story.

8th Period Review packets

Many of you failed to hand in review packets. Wedesday morning is your last chance. Right now I have Eric, Monique,Darryl, Ajay, Luis, Kate S., Megan, and Brittney. It is worth 5 homeworks and many of the rest of you did at least some of this, so bring it in.

Honors Review Packets and Book

Remember to bring your books and Review packets in.

All Students: Stuff on Ridge Computers

Just a reminder, if you any files on the school servers or hard drives you want to save, you must mail them to your home computers or save them to your personal portable memory devices pronto. Your files will be cleaned out over the summer.

Guaranteed A for AP students

I thought that might work. Make sure you turn in all the AP test materials and your books tomorrow. No this won't guarantee you an A, but it may help you avoid a D.

Important Honors Thermo notes

Here are some additional notes on thermo you should review for the final and give the sample a cycle a try. I will post the answers on Friday.

NotesonThermoR3.doc

Focal Length for Spherical Mirror

As promised, here is a demonstration that the focal length = 1/2 radius of a spherical mirror.

Please look it over, it is simple.

Derivoffforsphmirr.doc

Honors Projects Missing REVISED

My records are currently showing that I Have NOT received project proposals from:

81150; 85307; 200841; 202431; 81766; 204177; 204192; 85369; 80917; 83230.

CONTACT me IMMEDIATELY about this. I hope many of you are in a group that has submitted a proposal but I need to hear FROM YOU immediately.

Honors Review Packet

Here is the link to the review packet for this semester. This inlcudes you last homework assignemnts which will count for a total of six. They are to be done on clean sheets of paper and turned in when due. When you do the work make notes etc on the packets so you will have them to use at home.Keep the packets they are yours to keep and study from.

RevShtHonorsSpr-07.doc

Also, here is a preliminary Equation and Data sheet. I will be reviewing and revising it for use on the final exam.

FinalDefandEqnsR-07.doc

Great Adventure Flying Wave (Activity 12)

For those who did not go to Great Adventure, make sure to use 6m for the radius

Honors Unit 16 Schedule

Folks, many of you missed this today. I'd still like you to do the work for tomorrow if at all possible.

HonorsUnit16LightSch07.doc

Great Adventure Data

There is some information on speeds and heights for the Great Adventure Rides available at http://www.sixflags.com/greatAdventure/rides/AllRides.aspx. Pick a ride and hit learn more to see if this has what you need.

Relativity proof

For those of you who want to see a quick way of demonstrating that equations 7 and 8 are equivalent, using the transforms developed up to that point in the notes, see this link:

RelatvtyEqn8proof.PDF

Great Adventure Labs

Some Batman Activity packages handed out to students skip page A50. If you need a page A50, come see me.

AP Relativity Assignment for Monday AM

No, the quarter is not over. Your assignment, due for class Monday, is to demonstrate that if equation 7 is true [as it is if x , y and z are the coordinates of an expanding flash of light from a bulb at the origin] then equation 8 is true. Do this by substituting the transform equations for t', x', y' , and z' from page 10 in equation 8 and seeing what you get.

Happy algebra.

Thermo Test Corrections Honors Sect 1

My Honors Section 1(period 3) will have an opportunity to correct their last thermo tests on Monday night. You must ask for your tests back Monday and turn it in Tuesday with COMPLETE answers, with work where appropriate on a clean sheet(s). The corrections will be allowed to replace your orignal test grade to a large ( not complete) degree.

You must be ready to demonstrate that the work turned in is your own and you understand what you did to receive any credit for these corrections.

All Classes

Your assignment, amonst the other homework over the weekend, is to prepare your index card contianing all the data points you'll need to collect at Great Adventure. If you are not going, prepare one for the data listed on your data sheet. Make sure your name and group # are on the card.

THIS CARD WILL COUNT AS ONE LAB SO DO IT NEATLY AND YOU MUST HAVE IT FOR CLASS ON TUESDAY.

Enjoy the holiday and remember to commemorate those who served this country.

Honors Soccer Ball Lab

Folks, you were supposed to turn in calculations of the initial velocity of the soccer ball based on total time in the air, and height of the ball above ground as it passed the pole about 5 m from the launch point, and the total horizontal distance traveled. These measurements were made available to all for 3 or 4 trials. Get them from a classmate if you don't have them.

Once you have them you can use Time to top = vyi/g and Total time = 2 x time to top to find vyi

Then you can use this to find how long it took to reach the pole from the launch point from the fact that y = vyi tpole - (g/2 ) x tpole squared. From tpole and the distance from the launch to the pole you can find vxi. You can then figure out vx final. [Note that vx is not constant as we usually assumed because this real case had lots of air resistance.]

This lab will be accepted no later than Tuesday.

Honors Schedules

Here is the 72nd revised schedule for Thermo and a new one for Sound. Hope we can keep to these - its up to you.

Unit14Rsschedonly.doc


HonorsUnit15SoundSch07.doc

AP Relativity

At last, we can explore Einstein's revolutionary explanation of how the universe really works. Well at least the simple parts. Please download the following and read pages 1 through 7. This stuff is pretty hard so we will spend a fair amount of time on it.

NotesonSpecialrel12.doc

AP Special Assignments

Please remember any special assignment for which you have volunteered for this Friday ( period 1) and Monday (period 6). Remember, will be investigating the breaking strength of chips, the viscoisty of juice, and the energy content of pastry. We will need materials to contain these substances and to remove debris from faces, fingers, and table tops. Please do not forget you assignments.

Honors Thermo

Now that the dust of APs and Great Adventure is clearing I can tell you we will have a thermo test on Tuesday, May 22,.
Your assignment due Friday, May 18 is try the Carnot cycle on you grain elevator sheet. Note the 1/30 volume should be 1/3. Also review this link and for Monday, 5/21 draw PV diagrams for the other Carnot cycle given there.

CarnotCycleforGrainElevatorSheet.doc

For those of you who missed it review these notes.


NotesonThermoR2.doc

AP Projects

AP project proposals are due Monday 5/21. Projects are something you build and the physics of which you can explain. Proposals should describe the project, what physics you will learn and explain, and how you propose to build it.

Weekly progress reports are required. Projects must be complete by 6/11 since that's when the first presentations will be made.

Project teams can be 1, 2, or 3 people.

AP Interim Grades

Here are your grades. Many of you are suffering from lack of study group reports. Others suffer from the dangerous disease "nolabitis". Email me your study and lab reports by 9 PM and I will try to include them in your interim grade.

Qrtr4InterimsAP.xls

Fluids Test For Corrections

Here is the fluids test to use for creating a correct set of answers. Provide a complete (i.e., don't just correct what you got wrong), clean, perfect set of answers showing work and get 30 out of 30 points on a quiz. Any less than 90% correct and you will get no credit, so be careful. Due tomorrow for those without any APs left for this week, Thursday for those with one AP, and Friday for those with more than oneAP left this week.

TestHonFluidDyn-07Post.doc

Good Luck,

Dr. Cherdack

Revised Honors Thermo Schedule

Sorry folks, but since we lost some ground last week, I had to revise the schedule. Try to keep to this one. Do your best to do the homework and ask in class if you really need help.

HonorsUnit14therm07r1.doc

Honors Assignments on Thermo

Here is the schedule for Unit 14 Thermodynamics.

HonorsUnit14therm07.doc

Please catch up as soon as you can.
The following three assignments are due NO LATER THAN THURSDAY

1) Read Sec 10-1,2,3 and Thermo Notes Do Chap 10: 1,2, 10, try#17
2) Read Sec 10-4 Chap 10: 18, 25,26,29,46,47
3) Summarize thermo notes including heat engines; complete Chapt 10 # 17 to be reviewed in class Do Practice problems 3-7

AP Take Home Test

ON the signup sheet for which test is to be considered homework and which to be considered as a test I noticed a trend. Many more students chose to have the FR counted as a test and not the MC. Let me make two points:

1) Low numerical scores on the MC are still high letter scores and I will mark the MC scores accordign to AP methods wherein 60% correct is probably the equivalent of a 95 or more.

2) This was an attempt to restore my faith in your integrity not a chance for you to optimize your grade by choosing to have only your highest test score counted. Many of you scored much higher on the FR than the MC and a disturbingly similar trend showed up on who chose the FR to be counted and not the MC. This seems like evidence that many of you misunderstood the purpose of the process and are still just pursuing a high grade at the expense of more important things.

Therefore, if you opted to count the FR but not the MC, unless I hear from you otherwise in a pretty convincing way, I will assume that if you did not believe the MC was honestly taken as a test, than the FR should also not be considered as a test. As I said, let me hear from you if you did really take the FR as a test but not the MC. Those of you who opted for MC but not FR or who said both were tests or both were homework need not respond.

Fluids Quiz Opportunity

I am giving you the opportunity to have a 30 point quiz consisting of correcting your last fluids test. Get 100 on your corrections and you get 30 points on this new "quiz". Less than 90 and you will get no credit, so do it right. You may ask for help but you cannot copy. All work must be your own and you must show complete understanding of the work you present. I reserve the right to question you and failure to show understanding will be deemed evidence of cheating. When you turn in the corrected test: all the work and answers are required ( including stuff you did right the first time) on new clean neat sheets. You also must turn in the question sheet with your name ( and the original owner's name if present) at the top. See me if you need a question sheet.

Honors Thermo

Honors Students Please see post on thermo notes from January 8. Download the second and third posts . The first one can wait until you are pretty comfortable with thermodynamics.

AP FR Homework

Here is the FR assignment due Monday ( Tuesday if you are taking an AP test on Monday).
b_physics_b_frq_02_10379.pdf

2004 FR

Here are solutions for 2004 FR

APFR2004Soln.PDF

Notes on Fluids

Here is a better set of fluids notes
NotesonFluidDynamics.doc

Revised Astrophysics Program at Rutgers

[ I have included the address for another web page that explains the program a bit better] We are looking for a few good students interested in learning about x ray astronomy in cooperation with the Rutgers Astrophysics program. It involves attending a four week summer course and then doing research and attending monthly meetings during the school year. It is a chance to create your own research and learn how to download and manipulate the same data astrophysicists use in the course of their research. Deadlines are coming up very soon so go right to http://www.physics.rutgers.edu/asi/asi_general.html and see if you would be interested. If so go to http://www.physics.rutgers.edu/asi/asi_student.html and begin the application process and then contact me or Mr. Gilmore immediately.

Honors Projects

Projects ARE REQUIRED for the 4th quarter. They should be something you can build, demonstrate AND EXPLAIN. Proposals for Honors Physics projects are due Monday 4/30. Proposals should be clear as to what you plan to create and how it works.

Subjects which are acceptable include:

fluids, sound, electricity and magnetism, light and optics. ( Newtownian mechanics and rotational motion are not acceptable)

Ideas include motors, speakers, generators, musical instruments, telescopes and microscopes, micrphones, spotlights, fluid systems demonstrating Bernoulli's principle.

Good Luck

Revised High School Astrophysics Research Program at Rutgers

We are looking for a few good students interested in learning about x ray astronomy in cooperation with the Rutgers Astrophysics program. It involves attending a four week summer course and then doing research and attending monthly meetings during the school year. It is a chance to create your own research and learn how to download and manipulate the same data astrophysicists use in the course of their research. Deadlines are coming up very soon so go right to http://www.physics.rutgers.edu/asi/asi_general.html and see if you would be interested. If so go to http://www.physics.rutgers.edu/asi/asi_student.html and begin the application process and then contact me or Mr. Gilmore immediately.

AP MC and Free Response

I will probably post some solutions near the end of the vacation so keep checking the blog.

Reminder The 1999 and 200 Free Resp and the MC #1 are for practice. The other Free response and MC #1 are a real take home test.

Compton Scattering

Compton scattering results from photons colliding with electrons. In these reactions the photon loses momemntum thus its wavelength increases.

lambda post collision - lambda original = [h/ (mass of electron x c)] [1-cos(theta between ooriginal direction and final direction of photon)]. This angle is usually called phi but not in your text.

Fluids Notes for ALL and Honors Schedule ,Rev Sht

Here are notes on fluids for everyone (AP should have hard copies already), and a schedule for honors and a review sheet.
NotesonFluidDynamics.doc

HonorsUnit13Fluids07.doc
ReviewShFluidDynamics.doc

AP Practice

Try to get throught the entire AP Test Package your received today by Monday. I would like to go over the most troubling problems with you on Monday.

Enjoy the weekend.

Honors Assignment

Your assignment for the weekend is to write a report on the magnet strength measuring device development lab we did on Thursday. I strongly suggest you develop this lab report in groups, but each report must be written in your own words. It is due Monday

Key ideas: Goal is to find B of the permanent magnet.
The force was measured by using a balance to get readings with and without the magnet near the solenoid ( coil). so Fmagnet on solenoid = F solenoid on magnet= (Mwith-Mw/o) x g

Magnetic Field generated by solenoid is Bsol = mu0 x I solenoid x N turns (500 in our case)/ solenoid height ).

F solenoid on magnet= L IPermMag x B sol.

Where IPermMag is the equivalent current in permanent magnet and L is the perimeter of the permanent magnet.

Then B PermMag = mu0 IPermMag/height of Perm Mag

Enjoy your weekend

Modern Physics for AP

Here are the notes on Modern Physics for you to read this weekend.

ModernPhysicsReview.doc

ModernPhysicsSummary.doc

AppendicesRevModPhys.doc

Perhaps we'll have a reading quiz on Monday

AP Light Problem Sheet

Here is the link for the Unit 14 B problem Sheet

Unit14Aproblemsheet.doc
Ignore the 14 A in the title, I used to teach Physical Optics first.

Honors Magnetics practice problems

Here is the link to the schedule with the parctice problems attached. See you tomorrow.

HonorsUnit12Magnetics.DOC

Currents and Circuits, Circuits Lab

Many of you still seem to not understand that currents arise when a potential difference (i.e. voltage drop) is placed across an element. This creates a field which makes electrons have an average velocity in the direction opposite the field ( because thay have a NEGATIVE charge). Tis flow of electrons is the current. The current through an element depends on the voltage drop across that element; it is not some magic fixed number which is always the same. The total current depends on the overall conductance [or 1/ (Rtotal) ] x Von the whole circuit.

Many of you also do not seem to understand that the voltage source provided V Joules per Coulomb and that the joules per coulomb ( i.e. volts) lost by a charge going around the circuit must add up to the Voltage gained from the voltage source.

ALSO SEE 2 previous posts 1 On Bulbs and 1 On Circuits

Grades and Mandatory Study Groups

Study Group Meetings are Mandatory for 3rd Quarter for Honors and AP.
The rules are
Honors: no meetings no grade for quarter. One meeting lose 2.5 points. 2 meetings lose no points.

AP: fewer than 3 meetings no grade; fewer than 4 meetings lose 5 points.

You have until Tues AM to fix this. Each person must submit a report for each meeting covering time/date, place, subjects discussed.

You must meet outside class hours. NO faking reports .



Here are what my records show for those with fewer than the required meetings by Student ID:
AP Period 1 3 meetings: 80873, 85763, 201269, 201972, 2 meetings: 82845 all others 4 or more
AP Period 6 3 meetings: 300484, 82360 2 meetings: 81130, 80320
Honors Period 3 0 meetings: 80178, 204134, 202381, 201256, 80930, 84400.
Honors Period 3 1 meeting: 80845, 200841, 80911, 202431, 85194, 81700, 201112, 85306, 81766, 83290

Honors Period 8 All have 2 or more, nice going.

AP and Honors: Circuits with Bulbs

I have uploaded a solution for a problem essentially identical to the one I gave honors as their circuits lab and also similar to the questions in the AP circuits lab. Honors students please note that here I have used bulbs A and B as 3 W and C as 6 W. These are all the rated power when there is 12 V across the bulb. If the voltage across bulb A, VA, is less than 12 the power used by bulb A will be reduced.

Many of you in AP and Honors still do not have a clear understanding of the fact that current is caused by a voltage difference (or voltage drop) across an element. If you remove that element its current no longer exists. Sometimes some current will increase elsewhere in the circuit, but this is because voltage across that part of the circuit has increased. Batteries produce nearly fixed voltages. The current flowing to and from the battery varies inversely with the circuit resistance. Removing part of a parallel branch removes a number of electrons that were subject to fields in that part of the circuit and thus reduces the current in the circuit. Another way of saying this is removing a parallel element increase the circuit resistance (decreases the circuit conductance).


Here is the solution set

BulbCircuitSolns.PDF

Notes on Magnetics for Honors (and AP )

Here are some notes on Magnetics. Down load and read them. AP students should already have done this!

NotesonmagneticsR4.doc

Spherical Mirrors Derivations

Here is a derivation of the fact that f=R/2. It is the most direct one and one of the simplest ones I could think of.

Derivoffforsphmirr.doc

Here is one for the equation relating focal length, distances, and image sizes. It is slightly different from the one in the notes.

Derivlenslawsphmirr.doc

Circuits/currents Labs for AP and Honors

This is relevant to both AP and honors classes. I have reviewed several labs from my AP classes and I found nearly everyone still fails to understand what causes currents. We began this subject with a discussion of how a current through a conducting element or object RESULTS from a field through it. The field through a conducting element is directly related to the voltage across it. Thus the current through an element depends on the voltage across the element and the property of the element known as its conductance, or
I = V x conductance or more commonly

I= V/resistance where resistance ,R , = 1/ conductance.

Thus if you hook up a battery to three bulbs, R1, R2, and R3 in parallel and then disconnect R1, the total current through the battery drops but the current through R2, which is due to the voltage across R2, does not drop because the voltage across it did not drop and its resistance did not change. [ If they were in parallel, the current through R1 never went through R2 or R3.] Yes the total current did drop but not the currents in each of the two remaining bulbs. The battery produces less current but about the same voltage. If R2 and R3 are in parallel with each other and then the pair is in series with R1, if R3 is disconnected, less current will flow through R1 so V1 across R1 must have decreased and V2 across R2 will increase because V1 + V2 still must equal Vtotal from the battery as before. Thus R2 will have more current through it, more voltage across it and produce more power. The reverse will be true for R1.

In fact when one in three parallel bulbs goes out, slightly more voltage is available to the remaining bulbs because the current flowing through the battery and thus through the small internal resistance in the battery is lower, reducing the internal voltage drop in the battery. This means the battery output voltage will go up slightly. AP students should have noticed that the voltage in part A of the lab with its small total current was higher tan in Part B, with its larger total current. Honors students should also become aware of this small effect when you find the drop in R internal for the series (low current lower V drop across Rinternal) and parallel cases (high current higher V drop across Rinternal).

Another point about those labs. No one bothered to fill out the ehadings on the first sheet of the lab report. While I admire your attempt to conserve the precious resource, ink, you will have to fill these out on each first page to receive full credit on this lab and all future ones. This goes for Honors as well. Name , Date of Lab performance, Period of your class, Lab group members who participated, must appear on the first sheet of all labs.

If R2 and R3 are in parallel with each other and then the pair is in series with R1, if R3 is disconnected, less current will flow through R1 so V1 across R1 must have decreased and V2 across R2 will increase because V1 + V2 still must equal Vtotal from the battery as before. Thus when R3 is disconnected, R2 will have more current through it, more voltage across it and produce more power. The reverse will be true for R1 when R3 is disconnected.

Electrons and currents

Currents are caused by moving charges and the measure of current is the number of coulombs passing by a point per second. IF a current is caused be electrons and each electron has a charge -1.6x10-19 Coulombs, then the number of electrons passing the point where the current, I, is measured is given by:

[I/1.6x10-19] electrons per second

We drop the - sign because we are interested in magnitude not direction. The - sign just means that the current is in the direction opposite the direction the electrons are going.

Honors project

The project can be a report, a lesson for the class, or a lab including instructions, list of equipment, and sample completed lab, or something you can build and explain ( in writing and orally). It can cover anything we have done or will cover this year. It must be in your words and something you develop. Cut and pasted downloads or the equivalent will be considere zeros. Cut and pasted downloads, etc. passed off as your own work will be considerd cheating!!! so don't do it. You may work with up to 2 other people. It should be about 10 to 12 hours of effort per person. Less effort will receive smaller weighting in calculating your grade. The project grade will be roughly 45% what you learned doing the project, 35% what someone else will learn from your project and 20% polish and quality.

AP Optics Readings

Here are three sets of info on optics you must read. We will not cover this in much detail in class. SummaryofGeoOpticsrev3-07.DOC

NotesonGeometricalOptics.doc

PhysicalOpticsSummaryrev3-07.doc

Magnetic Fields in an accelerator

A revised calculation for the Fermilab Tevatron B field.

The magnetic force provides the centripetal acceleration in large acclerators, i.e.
QvB/=mv^2/r ;
so for a proton held in circular motion by a magnetic field we have:
r =mv/eB and
B= mv/(r e) ( where "e" is the charge on a proton). At relativistic energy mv = E/c; where c = speed of light = 3E8 m/s. For a proton in the Tevatron E = 1E12 eV (where 1 ev =1.6E-19 J) and the radius is about 1000m
Thus we have:

B= [1E12x1.6E-19/3E8]/[1.6E-19x1000m]= 3.3Tesla or about 66000 times the earths magnetic field and about half of what the big coils on a fusion reactor would create.

Honors Unit 11 Schedulke

Here is the link for the revised schedule for Honors Physics Unit 11 Electric Currrents and Power.

HonUnit11CurrntsSch07r1.doc

Please do as much of Mondays's assignment as you can today. it will make the rest of the week much easier.

More AP Magnetics Stuff

Links to notes and worksheets and problem set:

NotesonmagneticsR4.doc

Unit13Worksheet1.DOC

Unit13Worksheet2.doc

Unit13ProblemSheet.doc

I will make some hard copies available but if you are printing this out let me know so I won't kill any extra trees.

AP Unit 13 Magnetics

Here are the schedule and Practice Problem Set for Unit 13

APUnit13Magsched07.doc

AP Lab Reports

According to the College Board, many colleges will require you to show evidence of laboratory work to get advanced placement. In other words, hold on to your lab reports!

Extra Credit for Black Hole Lecture

My records show the following of my students attended the lecture on black holes at Rutgers on 3/3:
Dan Ryan, Andy Lee, Tina Aliprando, Alec Roelke, Ian Stanley, Lee Stevens, Christina Vivello, Neela Kumar, Michelle Samuel, Aaron Rosenberg, and Brittany Durrant. In addition I recognized Justen and EJ from the physics club. Let me know if I missed anyone.

My students who attended are elegible for some extra credit for writing a summary of the presentation. It should be at least three paragraphs. Topics you might include are: how the large black holes can form along with a galaxy; how they emit energy large amounts of energy( obviously we are talking about energy emitted by stuff before it enters the black hole); and how they are detected using our understanding of gravity and the motion of objects around a large mass. The role of dark matter in black hole and galaxy formation could also be discussed.

AP Practice Free Response

Refer to the the AP Free Response Questioon package you were given before February break. For Monday 3/19 do 95#2 96 #2 ,#4, 97 #1. Try on your own, really try, and then work with your group.

Honors Unit 10 Electric Potential

Here is the Schedule for Unit 10 Electric Potential. Note Changes from hard copy distributed in room 506: homework from Friday 3/16 onward has been advanced to an earlier date by one day. The quiz will be on Thursday 3/22
HonorsUnit10ElecPotsch-07r1.doc

AP Unit 12 Currents

Here are your AP Unit 12 Schedule and Worksheets 1 and 2.

Unit12APSched-07.doc
Unit12Worksheet1.doc
Unit12Worksheet2kirchhoff.doc

Honors Electrostatics Retest

As a prerequisite for the electrostatics retest, you need to submit a complete corrected copy of the first test we took last week. This copy is due tomorrow, 3/8,by 7:35 AM for my 8 th period class, and by classtime for my 3rd period class. The score on your retest will be multiplied by the percent correct on the corrected test you will be turning in tomorrow.

Honors Study Groups

Every honors study group must meet for at least one hour every two weeks. Each member must turn in a brief report of the meeting. Failure to do so will result in an incomplete for the quarter. If you have a problem with this, let me know.

AP Tests

AP students: register for the test on line and turn your transportation form in to guidance. The physics B test is Monday afternoon May 14.

Black Hole Lecture Reminder

At Rutgers Saturday 3/3 2 PM at the physics lecture hall.

A Leading Expert on Black Holes will presetn a lecture aimed at popular audiences. BE THERE

See me for directions and more info

Revised Harmonic Ocillator, Period and Why gravity doesn't matter

The Harmonic oscillator period is proportional to the square root of the mass, because the acceleration is inversely proportional to the mass, and period is proportional to 1/the square root of the acceleration. This is just as true in vertical and as in horzontal oscillators.

The period's relationship to the mass has nothing to do with the spring having to overcome greater gravitational force. The gravitational force is "automatically" canceled by the spring being stretched to its NEW EQUILBRIUM position. In other words the force the spring exerts on the mass while in the new equilibrium position already is equal to mg upward. Thus , if we add this +mg from the spring into our equations and also add the -mg due to the force of gravity, they cancel and we are left with exactly the same equations about the new equlibrium position that we would have for a horizontal spring/mass about the original relaxed (equilbrium) position of the spring. See me if this not yet clear to you.

Harmonic Oscillator Vmax is proportional to A not sqrt A

In your ocillator lab reports, a large number of you are telling me that Vmax is proportional to A^1/2, despite the fact that your graphs clearly show Vmax is linear with A, NOT with the square root of A. In fact your graphs all show that Vmax =omega x A. All of which makes the fact that you answer the question saying Vmax is propoertional to A^1/2 a complete mystery to me. From where are you getting this misinformation? In any case, please correct your reports.

A, of course is amplitude, which is the maximum displacemnt from the equilbrium.