AP and Honors Quizzes

We will be having substantial quizzes on Teuesday. AP quiz will include up to torque.

Honors quiz will include all we have done on force and motion, work and energy up to, but not including flux and Gauss'Law. Ask me how the test will be scored vis a vis last test in class.

AP

For tonight, also:Calculate the orbit radius for a geosynchronous orbit and the speed (m /s and mph)

Honors Test Important

If you had a test with a number greater than 20 and MC #6 was marked as wrong, see me. It may pay you to do so.

F/m and PE gravitational

Some students tried to find acceleration by dividing Fnet by meters traveled instead of mass. This despite a few labs on the subject.

Many of you didn't even bother with Fnet and chose whatever force popped into your mind first either Mg or Frope. Only a few found the sum of Frope + -Mg

Most of you also decided that even though the elevator rose, it lost PE.

Important to all students KE and PE

Delta KE =-Delta PE only when there is no net work done by or on the system. A more complete statement of energy conservation is for a system.

Win + Heat in= Delta PE + Delta KE + Delta U ( change in thermal energy)

This should be well known to those doing energy readings.

. In fact you should all read this latest, hot off the press, revision. This will give you AP students a leg up on future work. If you do not have time now make sure you note the post and comeback to it. Honors and Topics folks, read it now.

http://h1.ripway.com/DrCherdack/Notes%20%20Work%20and%20Energy%20R5.doc

Fnet is not MG unless gravity is the lone force on the object.

Fnet is not mg if there are forces like ropes or normal forces acting on an object. I had no idea why, when you are told a rope is pulling a bucket up with a force of 105 N, you can say the net force on the bucket is Mg, but I think see the problem now. You think a and - g are interchangeable. a =-g is only true in free fall when gravity is the only force. Too many FORMULAS, too little understanding. Clearly you still do not know that Fnet is the vector sum of the forces on an object even when this fact is printed at the beginning of your test, or you do not understand that things that have forces on them other than gravity do not accelerate at -g. By now you should have noticed that not everything on earth is accelerating downward at -g. Since this course is about the real world and the real world is full of objects not in free fall you do, now , I hope, realize that a does not = -g in general and certainly not when a rope is pulling upward with a force greater than Mg.

Mass vs Charge

The number of students in my honors class who did not distinguish between charge and mass is very alarming. Mass of a proton = 1.67^-27 kg as does mass of a neutron. Charge of neutron is, you guessed it, zero. Charge of a proton is 1.6x10^-19 Coulombs. Its time to start understanding that these symbols, Q and M, are real physical quantities. By now you must know that electric fields act on electric charges through F = Q Efield and that

a=Fnet /mass not /charge. Do not make these errors again.

Honors Unit 4 Schedule

Here is the schedule for our new unit on electric forces fields and potential

http://h1.ripway.com/DrCherdack/HonorsUnit4SchedA.doc

AP Unit 4 Assignments

Here is your Unit 4 material

http://h1.ripway.com/DrCherdack/APUnit4schedrotmot09-10.doc

http://h1.ripway.com/DrCherdack/Unit4AP-09-10ProbSh.doc

http://h1.ripway.com/DrCherdack/planets%20or%20Satellites%20in%20Orbit.doc

http://h1.ripway.com/DrCherdack/NotesonTorque%20rev%2012-30.doc
http://h1.ripway.com/DrCherdack/PlanetWS.xls

http://h1.ripway.com/DrCherdack/ProblemSheetR-1rev1.doc

http://h1.ripway.com/DrCherdack/ProblemSheetR-2.doc

http://h1.ripway.com/DrCherdack/Problem%20Sheet%20R-3A.doc

Assignments

Please try the oncourse links one more time. They may have gotten some of the bugs out. Let me know if you still cannot download. In the mean time I will post them on my usual server in the evening. Check back here around 7:30.

Lab Link

It looks like my file storage server is back up. Here is one for our next AP Lab. Look it over and print it out. The trouble may have been malware infecting the 506 desktop. It did have 15 infected files. It has been cleaned up, but I'll try to do my uploads from home which seems to be safer.

http://h1.ripway.com/DrCherdack/CentripetalForce08-9.doc

Honors and AP schedules

Schedules are now posted on homework and events October 23. Note on AP schedule the planet worksheet is the file named SolarSystem.xls

Honors Schedule

I have developed a schedule of our new unit: Unit 4 Electric Forces, Fields, and Potential. Unfortunately Off course is busy upgrading its document features so it won't allow me to upload the schedule. At least when they are done I may be able to see my documents in alphabetical or chronological order. Right now it displays them randomly; not too useful when you've got a couple of hundred documents to search through.

AP Assignment

Do Assignment 3 on Mastering Physics. New Unit Schedule will be posted soon

Honors Assignment

Re read Chapt 16 Sections 1 through 5 and Notes on Electrostatics. You really need to do this! There may be a quick quiz to ensure you do. Do Questions 1,8 Problems 3,5, 25 (use F=QE in reverse) A new schedule for unit 4 will be posted soon

AP Assignment

My first upload of the rotational motion definitions got corrupted either by viruses on my laptop or our network or by Oncourse. The new upload works so things should be okay for now.

AP Assignment

For tonight Read Definitions for Rotational Motion pages 1 and 2 posted as tonights' assignment on homework and events Also read Chapt 6 Sect 1 and 2 . Do conceptual questions 1,3, and 9 and problems 1 and 7.

Interesting Physics and Astronomy events

This is from Bergen County College, about 50 minutes away in Paramus ( the home of campmor for you outdoor types and 4 big malls for the shopaholics).

Our Astronomy Lecture series continues and we hope that you will be able
to attend our October 29 talk given by Dr. Steele Hill about the SOHO
Solar Observation mission and/or our November 5th presentation by Dr.
Jim Gates on Supersymmetry and CERN. Both talks will start at 12:30 pm
in our Technology Building room TEC-128.
(http://www.bergen.edu/images/pr/campusmap-10-07.gif). Directions to the
campus are at http://www.bergen.edu/pages/1690.asp. We encourage you to
urge your students (high school and college) to attend as our speakers
are eager to have them at the talks. Therefore, I am urging you

Honors Assignment

Despite telling me the assignment is posted and showing it to me in my view, Offcourse systems won't let you see it in the public view. They are protecting you from seeing an assignment a day before it is due. The reason I did not post it Tuesday, today, was because the notes I wrote for the AP assignment would then also appear with the Honors assignment and I did not want to confuse you. I forgot about this wonderful feature of Offcourse. I am sure there is a way to work around all of this and I just can't wait to spend the oodles of spare time I have just learning what it is.

You can see why I preferred my private free file storage service to Offcourse which the school system pays for.

Honors WS2

The worksheet is now posted on Oct 21 in homework and events. Don't just not try. Use all you've learned to figure out how to do it. Sometimes something is missing, but you can find that something from the information you have and the physics relationships we have studied.

Honors: The Conservation of Energy Lab

Lab is a mini but have a good discussion of energy conservation, i.e. PE lost is KE gained. and make sure you compare the two not just say they are the same. Consider % difference. This is found from

(- delta PE - Delta KE)/(-Delta PE) x 100 (to get percent)

I'd say anything less than about 8 % was pretty good although I've seen some in the 1 % range in the past.

Note the last column should be - delta PE since delta PE is a negative number and you want subtract the KE from a positive number.

Assignments Again

Current Honors Schedules and workshhets can be found on events and homework posted Oct 15 and 16th and see some notes posted on the 12 th ( ignore the schedule posted on the 12th). Current AP schedule and worksheet are posted on Oct 19th.

Assignments and Schedules

I am posting schedules and materials on the homework and events pages of my website. Do the homework as called for in the unit schedules and on this blog. the fact that an assignment is posted on a particular day does not mean it is due that day. Nor does it mean its all that is due that day.

AP assignments

Unit 3 schedule and WS 3 are now posted on homework and events Oct 19

Honors Labs

Many of the lab on acceleration reports had the same old problem. You used the same data to form and confirm the equation. You need to test an equation against quantities derived independently of the equation you are seeking to confirm.

Consider the questions I asked you.


I asked you what the mass was. I asked you what the force was. What can you find from this information?


Next I asked you did the slope of the graph confirm a kinematic equation. Many of you said sure the slope = 2 a and then proceded to prove by showing how 2a = vf squared/delta x. This is not a laboratory proof it is a restatement of our theory. Then you calculated the slope and said it sure equaled 2a ( some actually dropped the 2 and said it equalled a) by comparing it with the a you found from the very graph the slope came from. This proves nothing except you can get the same answer from the same numbers. You must compare the a found from the slope to a from some other way of finding a. Now think about the first two questions above and if they offer another and independent way calculate a. Now if that other a and 1/2 the slope are equal, you can confirm the validity of our kinematics equation. Remember, this is physics. If nature does not confirm it, it isn't right.

Honors Labs

The accleration lab reports were mostly pretty good. However, there is still some sloppiness in wording. Many of you said that the velocity increases as the distance. While it is true that the velocity does increase when the distance increases, the phrase increases as means proportional to. i.e. if a increases as b then a = constant x b. Therefore it is v squared that increases as distance not v. This is crucial to the meaning of the lab which is meant to confirm one of our kinematice equations but more importantly, to lead you to the concept that force exerted over a distance changes energy.

A=F/m lab Revisited

Nearly all the labs from AP Section 1 and many from AP Section 2 have to be redone. You had to find Ma from the slope of the graph and Force from Mhanging x g and compare them. Most of you simply said Ma = force. Some of you compared your slope to the slopes for point on the graph. This produced the not very startling fact that the slope = the slope. However you thought it proved slope = force. F =Ma is not to be assumed. It is the hypothesis we were testing!!! go back and reread the post from October 10th and do the lab right.

Honors Force, Motion, and Energy WS 1

The WS is now posted as an assignment on Friday 10/16 on Homework and Events on my website.

Topics in Physics

Proposals for your report/presentations are due Monday. A proposal must include an outline of what you will cover including key physics and what relationships you expect to derive/explain/describe e.g dependence of flame speed on reaction energy and mixture density.

Honors Groups

Remember that each group must have met by Thursday for the Force, Motion, and Energy unit and each student must report on who, where, when and what was covered
but

EVEN MORE IMPORTANTLY by Monday each group should have prepared a brief outline including the system function and what important features of their system they will discuss (list several) and what key quantities they will produce such as nuclei per m3 and temperature for plasma; type and number of particles per sec for heating; field strengths etc. for magnets; vessel material and thicknesses for first wall and blanket; working fluid and flow rates for thermo; and currents for generator.

Make use of the fusion power plant study link I posted and the system issues I posted here earlier.

For more information ( you don't need to do much of this by Monday), look for links to (try the ITER site for some good stuff on these first three systems)
fusion plasmas, plasma confinement, transport in plasmas (probably much too much info here)
neutral beam heating and RF plasma heating,
tokamak magnets superconductors for magnets, tritium breeding and fusion reactor blankets, information on Rankine cycles, steam generators and steam turbines, helium brayton cycles if you choose a helium instead of steam cycle,
electric generators, power plant gnerators, large AC generators

Blog Links

My file storage site is still not working so assignments and notes will be posted at my oncourse website homework and events page.

However, keep checking the blog for other news.

Honors Energy Conservation Lab

Make sure your results for energy are in Joules so everything needs to be in m and kg. Remember work is force times distance and in this case your work in lifting cylinder is giving it potential energy. Note that as the cylinder the . This potential energy is then being converted into KE on the wasy down. So the change in PE is negative and the change in KE is positive, but they should be equal amounts.

If you are having difficulties, give it a good shot, but we will go over it on Monday. Since the report is not due til Tuesday for Section 2 you should have enough time to write your report.

AP Section 2 (4th period)

Please remember the homework problems for which you needed help so we can go over them tomorrow. Today's shortened periods coupled with you folks taking a while to do the lab prevented homework review today.

All Students: Links

Links to the server where I usually store my documents are not working at the moment so please look for assignments on my Oncourse website homework and events page.

Do keep checking the blog for news, comments, lab hints, etc.

Honors Notes on Electrostatics

Please destroy the version with the extraneous material on it and use version R1, now available on my oncourse website events page.

Honors Links

You're right folks the links don't work right now so I posted the schedule and notes on the events page on my website at oncourse

Honors Unit 3 Schedule

Here is the schedule for our study of force, motion, and energy.

The notes should prove useful. Although we will do potential more in the next unit, it will pay you to read them now.


http://h1.ripway.com/DrCherdack/HnrsUnit3SchedR1.doc

http://h1.ripway.com/DrCherdack/NotesElectrostatic3-08r1.doc

Honors Assignment

Read Sections 6.1 through 6-3. Do Chapter 6 problems 1,2,3

All Students Group Meeting Reports

Every student is to participate in at least one group meeting per unit outside of class hours.

EACH student is to submit an individual report ( not a group report) before the test for that unit, The report shall state who, when, where; and what was studied .

Honors students will begin this with this unit.

AP students are to meet once again for this unit and report on it.

All Students

The server where I load my assignments is having a problem, so go to the assignemnts events section of my website for the Unit 3 schedule and some notes you'll need

Honors

Bring in all your labs tomorrow. We will spend the day learning, I hope, how to describe, interpret, and draw conclusions from what we observe.

a=F/Mass Lab

I just finished grading one section. The vast majority of you said that indeed F= Ma or a=F/M. Unfortunately only a small minority bothered to support their conclusion with calculations. This is NOT GOOD ENOUGH. You must learn to go beyond doing the absolute minimum of what you are told. I asked you to support your conclusion. Some of you said the the acceleration went down as the mass went up. This is still NOT good enough. This would be true if M = Msquared times a cubed or square root of M times cube root of a, etc. You are to make calculations to demonstrate your conclusion. Why do you think I asked you to plot a vs 1/mass. Haven't we used the slope to find relationships from assemblies of data points? Isn't the slope of your plot Ma? Is is not something you can compare with the force ( hanging mass x g) to tell quickly whether or not Ma =F?

Some of you compared Ma with F for each run. This is fine, but using the slope tends to cancel out random errors that occur in individual trials in most labs.

Some of you had bad data that came from ignoring warnings about checking the photo gate heights to make sure only the top band was blocking the light in the gate. This was particularly true on the last trials, where the third bar tends to interfere with the gate light. You should know that where you measured tiny , or even negative accelerations, its because the second gate was reading some length different from what the first gate read. Similarly, an unexpectedly large acceleration should tip you off that you read a greater length in gate 1 than in gate 2. A glance at the data should tell you where you went wrong. For example a doubling of t from the previous run where you expected a 25% increase is a tip off.

AP Ferryman Lab

Most lab reports were pretty good. However many of you persist in the use of triangles in inappropriate ways. Try to outgrow triangles and think in terms of vectors and components. When drawing vector additions or triangles some of you seem to be incapable of placing the base at the top. In the ferryman Part 2 it seems natural to place the 30. m length at the top since it is the displacement along the north shore, but many of you drew it at the bottom and thus had the boat either going northwest or southeast graphically when it was of course going northeast.

Part 3: Some of you are still ignoring the process of finding relative velocity. You just assume that the 20 m/s vboat,water is a leg and the river current is another leg and you get a wrong right triangle. You need to use the idea that vboat, shore = vboat,water + vwater,shore and recognize that vboat,shore( the sum or resultant) must have zero x component. This leads to vboat,water's x component must = -vwater,shore ( also known as the current). In this case the addition of a diagonal vector ( one with north and east components) and an - east only vector ( the current) is a North only vector.

AP Quiz

Yes, we will have a quiz Tuesday, but it will really be a quiz, about 1/2 a period worth or less.

Honors Unit 3 Schedule

Here is the beginning of your new schedule using our brand new books. A more complete schedule will be available soon.

http://h1.ripway.com/DrCherdack/HnrsUnit3SechedPt1.doc

http://h1.ripway.com/DrCherdack/NotesWorkandEnergyR3.doc

All Students Homework

I have been looking at the homeworks, especially those that need help. YOU MUST IDENTIFY THE ASSIGNMENT. Worksheet number, Chapter and problem, due date all should be clearly identified.

Also, write down at least enough information so the nature of the question and your approach are clear. Much of what I see is worthless from the point of studying from and impossible for me to assess if you are doing things right because its disconnected scraps of information. Organizing your work o0n these problkems will go along way to organizing your thinking and improving your understanding.

AP Forces Unit 3

Finally, here it is, unlovely perhaps, but better than nothing:

http://h1.ripway.com/DrCherdack/APunit3sched%2009-10.doc

http://h1.ripway.com/DrCherdack/Unit_3_Worksheet_2r1.doc

http://h1.ripway.com/DrCherdack/Unit_3_Worksheet_3.doc

Honors 6th period

I think I may have said some things that scared some of you. When I quickly went through the three equations that can be derived relating displacement, velocity, acceleration and time, I did not mean to imply that I expected you to be fully familiar with them by Friday.

I wanted to show you how understanding a few simple ideas like displacement equalling time x average velocity and acceleration equalling change in velocity/ time could allow one to analyze and predict motion pretty completely. This was a preview of what will come in the course of our studies of motion and we will go over these equations more than once in the future. It is much more important that you see and understand where they come from then to memorize them and endlessly practice using them.

In the mean time, just knowing the definitions of average velocity and acceleration, and that vavg =(vi+vf)/2 and that vf = vi + aDt should suffice. You can use this information a bit at a time to solve problems without joining them up into more complex equations.

Honors Assignment

1) Identify which fundamental force is associated with;
Friction,
normal forces,
objects falling
planets in orbit,
ions circling in plasma

2) A mass of 14 kg is pulled with a net force of 42 Newtons north. What is its acceleration? If it starts from rest how fast is it moving after 3 seconds?. What was its average velocity during the 3 seconds? How far did it go?

3) What is the force on a tritium nucleus moving at 2 x10 6 m/s in magnetic field of 3 Tesla. What is the resulting acceleration? Does it make the tritium go faster or just change its direction to make it go in a circle?

AP Assignment

Almost finished with your schedule but not yet. Here is tonight's bundle of joy:

Read 5.1 through 5.3 Unit 3 WS-1 prob 1and 3 prob 5 with no friction

Unit 3 Problem Sheet 1,2,3,4

Save extra problems for the near future

http://h1.ripway.com/DrCherdack/Unit3problemsheet.doc

http://h1.ripway.com/DrCherdack/unit_3_extraproblemsR2.doc

Honors Quiz

Yep, it'll be Friday since we still need to do some review. I'll get some problems that address what you should have learned about 1 D motion up in a little while so stay tuned.

Honors Reminder

You must choose your power plant system by Friday

More on a =F/m

Plotting the graphs:
as for the horizontal axis where the quantity is 1/mass just do it the normal way you would for any quantity. You should start the scale at zero and it goes to about 2 (1/kg). Place the values where they belong on this scale . For example if a data point has a 1/mass = .67 it goes one third of the way from the origin to the 2 (1/kg) mark ( 2/3 is 1/3 of the way from 0 to 2).

We want a straight diagonal line increasing upward from left to right.

Honors Assignment

Try these for tonight and then we'll get back to kinematics.

Honors Unit 2 Force Work Sheet 09-2

1. A car is accelerating at 3 m/s2 to the north. If the car’s mass is 1500kg what is the net force acting on it?

2. A spring is stretched so that it produces a force of 20 N. How fast will it accelerate a 0.5 kg mass? Will the acceleration increase, decrease, or remain the same as the spring becomes less stretched?

3. A deuterium nucleus is placed in a magnetic field, B, with a strength of 4 Tesla. If the deuterium is moving at 2x106 m/s, what is its acceleration due to the field. [Reminder F=qv x B]

4. List the forces and their directions for a child going down a slide. Think about the two forces the slide produces and describe the role they play in the motion.

Lab Resubmits

Resubmits are due with in 5 days of your receiving them. I am rapidly approaching the point where I will no longer allow resubmits for poor use of graphs, not knowing what slope etc. means, and just plain sloppiness with regard to what acceleration, velocity, and dipalcement mean and how they relate.

Labs on a =F/m

Make sure you address the title question in your purpose, discussions, and conclusions. You must justify your conclusion. Think about using the slope to do so. Make sure you plot a vs 1/mass.

AP classes print your lab sheets for use in class.

Formal again and make sure you follow course guide.

AP Assignment

DO MC 24,25 problems 30 ,35, 41, 53, 67 (before it leaves the ground!)

Do Unit 3 WS-1 for problems 1 and 5 just draw the free body diagrams. For problem 5 identify the internal and external forces, considering the system to be the two masses and the rope between them.

http://h1.ripway.com/DrCherdack/Unit_3_Worksheet_1.doc

Corrected Honors Schedule

Here is a corrected schedule. By the way books should be in next week.

http://h1.ripway.com/DrCherdack/Hon%20Unit_2_Sched09-10-1.doc

AP Assignment

Read chapter 4 complete ( not much to do if you read already up to 122 as you should have )

Do conceptuals 17,19 MCs 21,22 probs 19,21 23,61

Read lab at link below

http://h1.ripway.com/DrCherdack/Lab%20on%20a%20=F%20divided%20bym%20AP.doc

Honors Assignment

Try this for tonight

http://h1.ripway.com/DrCherdack/Hnrs%20Unit21-DWS3-09.doc

For All Use words carefully

Many labs are plagued with sloppy writing of your thoughts or writing that reflects sloppy thinking. Words have meaning: the velocity is not the same as the rate of increase of velocity. Many of you say the acceleration is increasing when you should mean the acceleration is positive or non zero. Some of you have told me it is the acceleration that is increasing because the velocity is constant.



If the displacement is increasing at a constant rate then the velocity is not increasing, it is remaining constant.

If the velocity is increasing at a constant rate, it is the velocity that is increasing while the acceleration is constant. If the velocity is increasing at a constant rate, then the rate of increase of displacement is increasing. Note the double increase in this last phrase here.

Honors Fusion Power Plant Project Groups

By Friday of this week, you will need to have selected which portion of the plant you want to study in detail and for which you will come up with designs. I would like to have between 3 and 4 people per team, certainly no more than 4. E mail me as soon as you have made up your mind. Rank all 6 systems in order of preference and let me know which ones you really feel strongly about. I will try my best to give you your first or second choice but we will need a complete plant or we'll produce no power.

I have included some of what you will learn and some of what you will end up calculating or selecting. DON'T PANIC: you've got lots of time to learn about this stuff; after all your very final reports are due in June. The link to the European fusion power plant report I posted will provide you with a great resource. I will also provide many additional references as needed. YOU WILL NOT BE ALONE.

The plant systems are

1) Plasma including temperature, particle density, size, heating needs. This group will learn about plasmas fuse, how particles leave plasmas, and a little bit about waves in plasmas.

2) Heating using neutral beams and electromagnetic waves including ionization and neutralization methods, voltages, currents for neutral beams and frequencies and wave lengths for electromagnetic waves. This group will learn a lot about electric forces and microwaves.

3) Magnets for confinement ( and some heating) including toroidal, poloidal and ohmic heating coils, their purposes, the current required materials used and forces they generate right in the magnet itself. This group will learn details about the relationships between currents, magnetic fields, and forces; what it takes to resist forces. They will also learn about superconductors.

4) First wall and blankets to protect plasma from outside world, breed tritium, and protect magnets from heat and neutrons. Also must be compatible with the cooling system. materials, amounts, operating temperatures, strengths required will all be addressed here. This group will learn about materials strengths, resistant to heat, neutron absorption, heat transfer, and how to make a vessel strong enough.

5) Thermodynamic system to cool the lithium, produce steam and use the steam to drive a turbine at 60 ( or perhaps just 30) rotations per second. This group will learn about thermodynamics, transfer of heat, and the mechanics of using high speed steam to push a turbine blade. Key parameters to be determined are temperatures and pressures throughout the system and flow rates of steam required, and surfaces areas needed for heat transfer. ( If you like to cook, maybe this ones for you)

6) Electric generator to convert the mechanical energy from the turbine into electrical energy. This group will learn about how to create magnetic fields using current and then using these magnetic fields to generate much larger currents. The field strengths areas of coils, numbers of turns, operating voltages and currents are all key outputs from this group.

All students

Always keep in mind what you are doing. For example many students found the x component of a position and the y component of a position and the hypotenuse for that position which is fine. Then many of you used this to find the angle using you calculator's inverse cos or inverse sin functions and compared it with the angle measured by protractor. This is also fine although you should keep in mind which measurement, say 19 cm with a precision of 1/10 cm or degrees with a precision of a degree or two, is more accurate.

However some of you used the angle from inverse cos and inverse sin and then used that angle to find cos and sin again. This is circular reasoning. Starting with cos and using it to find the angle and then finding cos of that angle is just wasting time and demonstrating that you don't really know what the cos means.

Again, think about what your are doing and understand why you are doing it. DO NOT REDUCE THINGS TO BLINDLY FOLLOWING PROCEDURES AND USING FORMULAE.

Labs

Remember that our labs are part of the scientific method. All ( or nearly all) our labs have a purpose of confirming the theory we have established from observation, deduction , and some algebra. The projectile motion lab's purpose was to confirm our projectile motion equations relating v,delta t, a, delta x and delta y. This includes the fact that the y and x motions are independent except through a common time of flight.

The a =F/m? lab's purpose is contained in its title.

Your conclusion section should reflect the purpose of the lab. It should state whether or not the experiment confirms our theory and include a summary of the supporting evidence for your conclusion. This is the final step of the scientific method: reporting on the results of testing your hypothesis.

Note that if you use 3 different equations applied to two differing kinds of motion and your results come within 5 % of your prediction, it probably indicates your theory is pretty good. This is especially true if your equipment and measuring techniques are not perfect.

Honors Assignment

Complete sheet FS-1. Note that the force of gravity = 10 N/kg. ALso not that if there is no acceleration, it must mean that all the forces cancel each other out. For example a lamp hanging from a chain has a force from gravity pulling it down, but an equally strong force from the chain pulling it up.

Note that zero net force means no acceleration, but the object can still be moving with a constant velocity, it doesn't have to stand still.

AP Assignment

For Monday Read pages 105 through 122. Do Conceptual Questions 1,3, 7 and problems 1, 7, 11 ( show diagrams for 7 and 11) 13,15 . Assume rubber bands are identical.

Labs

The AP ferryman and the Honors a =F/m lab are both formal. Focus on the discussion, keep the purpose of the lab in mind both for the discussion and conclusion sections. In the ferryman we want to demonstrate our methods of finding and using components is correct as well as our way of adding velocities to find relative velocity. In the other lab the purpose is answering the quesion in the title. Make sure you do answer it.

All Students

You have no idea how rewarding and gratifying it is to create a second test for a unit , stay to administer a second test, rush to grade a second test so you can get the results right away, and then have the tests sit in the out folder because you cannot be bothered to look in the out folder.

This applies to labs and homeworks as well, so
LOOK IN THE OUT FOLDER EVERY DAY

All students

DO NOT WRITE ON TESTS...I am trying to cut down on wasted photo copying. so once again.

DO NOT WRITE ON TESTS points will be taken off next time

read this to yourself 50 times