All Students

Have a happy Halloween, and a safe one. After all I don't want you spilling your blood where it will be wasted.

AP Advanced Assignment.

The Torque lab advanced assignment is due on this Monday.

Honors Presentations

You have two project related assignments for this weekend

1) Each group should come up with two questions with which I can help them . They should be specific in nature so that I can walk you through what you need to know in 15 minutes or less. This is to make me feel useful. These are to be emailed to me over the weekend.

2) Each group has to provide me with hard copy of what they are presenting so I will have more than a vague recollection to go on after the class ends.

Honors Momentum Lab Reports

You lab reports must include a printout of the spreadsheets showing your results to be complete. I am not about to printout the spreadsheets from your emails, nor have I memorized your results.

Prepare the spreadsheet for printout as I showed you in class

with gridlines
covering two pages
in landscape
with the first 3 columns ( run number, Mass W, Mass D) repeated on the second page.

Honors projects

This what my records currently show. I certainly may have missed some emails with topics and URLs so come see me if you have some items not showing. If you have not submitted some items, Monday is the deadline. Presentation grades are for the entire group.

http://h1.ripway.com/DrCherdack/Projects10-27.xls

Honors Homework

Here is what I show at the moment


http://h1.ripway.com/DrCherdack/Honors%20Homework10-27.xls

Honors Retest

There will be a retest available to those who got below 35 as their score ( score not grade) on the last quiz. The usual rules apply. Your maximum grade on the retest will be the equivalent of a score of 35 i.e. a weak B-. You must email me by Friday 7:25 AM if you wish to take it. Your homework must be up to date e.g a homework grade of over 90.

AP Section 5 Pulley Labs

Section 5: I am missing about 1/2 your pulley labs. They are now 2 days late.

AP Retest

You can raise your grade to a 78 by taking the retest on Thursday. You must email me by Wednesday AM and be up to date with your homework to take the test.

Honors Schedule

Now that we have finished ( I hope) the dread momentum conservation lab here is the schedule for energy and work. Go back and make sure you have the Notes on Work and Energy and Notes on Energy Fundamentals from previous posts. If you do the reading this unit will be pretty straight forward and if you don't.... well just do the reading.

http://h1.ripway.com/DrCherdack/HonrUnit4EnrgyandWrk%2010-11.doc

http://h1.ripway.com/DrCherdack/EnergyandWorkWorksheet1a.doc

http://h1.ripway.com/DrCherdack/Hnrenrgy%20andlossProbs%20.doc

Honors Spreadsheets

So far I have received spreadsheets from fewer than half of you. I offered you an opportunity to get a bit more credit for doing something you had to do anyway. Now it looks like many of you will get zeroes for something worth half a lab.

I will bear this sad experience in mind in the future.

AP Material

here are the links: Read the "planets or satellites in orbit" notes tonight.

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/ProblemSheetR-1rev1.doc

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


http://h1.ripway.com/DrCherdack/ProblemSheetR-3.doc


http://h1.ripway.com/DrCherdack/Planets%20WS.xls

Honors lab

You don't need to graph anything. Do a good formal lab. The purpose is pretty obvious. Your discussion should cover how we calculated the various values and how close did we come to demonstrating what we set out to. The conclusion should refer back to the purpose and spell out if we made a case for what we tried to prove. Were our errors still small enough to make our case plausible?

Honors momentum labs

I don't know how much more explicit I can make this .The excel file you send me has to have your name in the file name. If it did not, send the file with a its new name again and tell me its a resend in the message subject line.
I don't need 42 spreadsheet files with the same name.

Honors Projects and Section 3 ( period 7)Homework

By now each group should have turned in its logo and name.
Each student should have turned the following 3 assignments 1) actual topics you will cover, 2) two key questions about your topic you think you answer in doing your project 3) websites you have used and a very brief summary of what you learned on the website and relevant text sections [Waves people should see fluids and waves chapters in text. They provide some important background to tides and riptides; but do not get wrapped up in wavelengths and sine waves].

Thus each group should have turned in an assignment and each student should have turned in 3 individual assignments.

Section 3

I looked over your project work and it ranged from very good to excellent. However it was also very incomplete. Homeworks turned in range from 13 to 26 assignments. You should ahve at the very least 24turned in.

Section 2 ( period 2) You folks are more complete but nearly no two questions assignment have been turned in yet. Please turn in assignments now if you haven't yet done so.


I will try to post my records on projects and home work by Tuesday so you can see what is missing. If you can't stand to have others see your project or home work records email me ASAP. Who knows I might even get the message before Thnksgiving.

Email

Its down again as of 11 AM Sunday. I'll check later to see if its up.

Honors Momentum Data

Here are spread sheets with all the values. Read the notes since I have edited the data in one run for each class to correct what I think were errors in reading or recording times.

Make sure you use your section's data.

Note there are no equations on these sheets. Your job is to replace the values with the correct equations in each line. To do this save the sheet with values first than save it as a file with the file name: yourname_momentumH2 or H3 depending on your section. Please use your own name not "yourname"!!!! Then email the file to me. This file will be considered a separate lab worth 1/2 a lab by itself.

The equations for the pD, pD', pW and pW' and for p'-p and delta pW + Delta pD, and %error are the same for all cases.

The equations for the velocities are the only ones that change from case to case. For the first runs with vW =0 if cart D is more massive than cart W ( or even equal) then TW2 gives cart Ds post crash velocity, vD' , because D kept going forward. If cart D is lighter than TD2 gives vD' and it should be negative, because D bounced backwards.

When vW (initial W velocity) not equal zero the vW is negative and is given by TW1, vW' is given by TW2 and is +, and vD' is given by TD2 and is negative.

If I get a chance I 'll post the equations after you turn your labs in.

http://h1.ripway.com/DrCherdack/MomentumvaluesHon3%2010-22.xls

http://h1.ripway.com/DrCherdack/Momentum%20valuesHon%202%2010-22.xls

AP Schedule

Correct link is now posted, but here it is again,

http://h1.ripway.com/DrCherdack/APUnit4schedrotmot10-11.doc

AP Unit 4 Schedule

Here's the schedule. Worksheets etc. to follow. Read the notes posted yesterday.


http://h1.ripway.com/DrCherdack/APUnit4schedrotmot10-11.doc

Honors Section 2 Data

http://h1.ripway.com/DrCherdack/Copy%20of%20Momentum%20Data%20Sheet%20Honors2a.xls

Honors lab data

I am giving you links to data sheets with the equations but you must make sure you understand where the equations come from and why they are right. Note that the velocity equations can change if conditions such as cart masses and which cart(s) is moving initially and direction matters. Jack and I did some of the Section 3 runs rerun of 6 and a new run 9 - in 9 we had car d stand still and car w moving at first. We may do few more trials tomorrow.

http://h1.ripway.com/DrCherdack/Momentum%20Data%20Sheet%20Honors2.xls


http://h1.ripway.com/DrCherdack/Momentumlabsect3.xls

AP Assignment

Here's tonight's assignment, stay tuned for Unit Schedule.

Read Definitions for Rotational Motion pages 1 and 2 and Chapt 6 Sect 1 and 2 . Do conceptual questions 1,3, and problems 1 and 7.


http://h1.ripway.com/DrCherdack/RotMotionDefseetc-07.doc

Honors Assignment Projects

Section 2 Those who did not present last week will present on Monday.

Section 3 each group must make a six minute presentation on their topics on Monday

HONORS 3 DATA SHEET

http://h1.ripway.com/DrCherdack/Momentumvalssect2.xls

Honors Assignment

For section 2 do the energy assignments that section3 did the other day see earlier posts.

For everyone:

1) Read these notes, they will help you a great deal. Do not worry about losses for now or about forces not in same direction as distance traveled.

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

2) Do the following problems [You can use the following equation

change in position = (vfinal squared - v initial squared)/(2 x acceleration)

to find the final velocity if you rewrite it for vfinal =.....(you figure it out)....


for falling objects and any other time you do not know vfinal]
(use g =10 for the acceleration of an object in free fall on earth )

1) A 4 kg flower pot falls off a shelf 3 m above the ground. How fast is it going just before it hits the ground? What is its KE. Compare it with Mass x g x change in height. Is this the work done by gravity on the pot? Is it equal to the loss in PE?

2) A 1500 kg car accelerates from zero to 20 m/s in 4 seconds. About how far did it travel ?( Figure out v average from vinitial and v final and use it to find how far the car went in 4 seconds.) What was the net force on it to cause this acceleration. Given Fnet and distance, how much work was done? What was the final KE? Are the work done and KE equal.

3) If you lift a 20 kg crate 12 m how much work did you do? How much PE did the crate gain? How fast will it be going if it falls back the 12 m? How much KE will it have gained falling the 12 m? Does this match the PE lost?

Cosmic Rays This Saturday

If anyone would like to learn about cosmic ray detectors and how to use them this Saturday and maybe become eligible for a summer program of paid study at Rutgers let me know ASAP.

Outside Physics and Science Opportunities

Those of you with a real interest in physics or other sciences should investigate opportunities to s participate in outside programs. Here is a list of examples I assembled over the past few years.

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

Columbia Master Class

Here is something people thinking about attending Columbia might enjoy.

http://www.studentaffairs.columbia.edu/admissions/events/sciencemasterclass.php

Honors assignment

What is the KE of a 1500 kg car going 30 m/s .

Was this the amount of work done on the car to make it reach this speed ( ignore drag and friction)?

If the car took 150 m to reach this speed, how great was the net force on car?

How much work does it take to lift a 20 kg book bag 4 m? Why do you have such a heavy bag?

AP Text problem 57

As far as I can figure it out the block will accelerate downward unless there is friction. Try figuring out the the required coeff of friction for it to remain motionless.

Honors Data Sheet

The link in the previous post now works

Honors Assignment

Section 2: use the data sheet to find vdoor, vwindow,vdoor',vwindow' and then for the first four runs find the momenta of the carts. See if total momentum is conserved. Remember to use signs for direction. Make sure you know which car went through which gate when.http://h1.ripway.com/DrCherdack/Momentum%20Data%20Sheet%20Honors2.xls

Section 3: answer the following: A 10 kg mass is lifted 5 m and placed on a ledge. How much work was done to lift it? What was the change in its Potential Energy (PE)? If it falls the the 5 m how fast will it be going, ( remember equations relating velocity, acceleration, and displacement - look over your a=f/m lab if you need help)? How much PE did it lose?

What will its kinetic energy (KE) be?


How much work is done by pushing a 50 kg mass with a force of 20N for 10 m. Assuming there no other horizontal forces, how much KE will it gain? How fast will it be going?

Missing Lab

If anyone picked up Alex Huynh's a=F/M lab please place it in the yellow out folder and let me know

Group Reports Urgent

I received a single study group report for an entire group. This is NOT acceptable and must be replaced by reports from each member

Honors Assignment

Read Chapter 6 the first 4 sections and read notes on energy fundamentals.

http://h1.ripway.com/DrCherdack/NotesEnergyFundament9-09.doc

Answer the following:

Force F acting for a time delta t changes p by delta p = F delta t. Write a similar relationship for force, delta x and energy.

When you lift an object without changing its speed what changes?

What is the change in potential energy when you lift a 1 kg mass 3 m?

I f you apply a force of 10 N for 3 m to an object what is the change in the object's energy?

Honors Momentum Problem Sheet

The correct answer for the the force vs time graph problem is a graph that is three times as wide and one third as high. For example it could be a triangle whose base runs from .05 sec to 0.5 sec and it should reach a maximum of about 8400 Newtons. The area under must be the same as the original since delta p is the saem because M(vf-vi) does not change.

Group Reports

See earlier post of Sunday 10/10: study group reports from AP are due on Mondays, from honors on day of quiz. These are required! BRING THEM IN

Honors problem Sheet

For problem 11 just find the velocity after the collision. The height requires that you know something about energy, and we have discussed this yet.

Honors

The honors test will now be a quiz given on Friday . This will allow full 2 periods for our computer lab for Honors Sect 3. Honors Section 3 make sure you bring all your a=F/M labs in with your data.

AP Test

The AP test is now a quiz and will be on Friday

AP Quiz

The quiz on forces will be on Thursday. Problems and questions will focus on important ideas not super manipulations of equations.

Honors Homework

Your schedule should call for problem 10 instead of 9 on the extra problem sheet. Problem 10 is tough so don't kill yourself over it but give it some thought. We'll try to get to it tomorrow.

AP and HONORS Group Reports

Written group meeting reports are required for every unit from honors. Due on test day for the unit

Weekly reports are required for AP classes. Due Mondays.

Meetings are to take place outside of class hours and should be at least 40 minutes long. Attendance is to be in person unless absolutely impossible for someone to physically attend.

Reports are required from each student and contain the following:

Place

Date

Persons present

Topic discussed (real topic including Unit name and number, not just problems, or homework)

All Students (and the rest of you in my classes)

I learned from back to school night that a few of you are spending too much time on physics at home. Yes you read that correctly, it is possible to spend too much time on physics. Do not spend more than 90 minutes a night on problems unless you have the time and energy to spare and you are enjoying the challenge. If you are stuck, try your group members first. if that doesn't work, you can always email me or ask me the next day.

You should be spending about 7 to 8 hours a week outside class on this subject, probably the toughest course you'll take at Ridge.

In any case coming to school alert is more important than solving every bit of homework.

Honors Projects

1) I should be receiving emails which contain links to sites you plan to use and a paragraph describing your topic in detail and what you learned or hope to learn from this site(s) in your own words

2) Try your best to catch up on your momentum homework without exhausting yourself. Bring an alert mind to school.

3) Particle Physics group: here are some notes for you. Go through the energy notes first, we'll cover this in our next unit after momentum. Nest read the particle physics notes. Don't spend much time on the equations, and relativity but do try to get familiar with the ideas and vocabulary of the particles and forces. An important concept is that energy can be converted into matter, (Mass=Energy/c^2) so fast moving particles can interact to create new particles with more mass than the original particles had.

http://h1.ripway.com/DrCherdack/NotesEnergyFundament9-09.doc

http://h1.ripway.com/DrCherdack/Notes%20On%20Particle%20Physics.doc

AP Retest

The AP Retest will be given tomorrow. I know there are difficulties, but my experience indicates that delays will only reduce your readiness.

Honors Test

Nice Work guys, average was about 84% correct.

AP Projectile Motion Lab

The lab's purpose was not to find out how far the ball would go. Nor was it to improve your already immense prowess in projectile motion. It was to confirm the concepts and equations we use in calculating projectile motion. Even an error of 5 or even 10% is not so terrible when you consider that the predicted distance was the result of several rough horizontal and vertical measurements and 4 sequential calculations.

Honors

Remember tomorrow is a project day. Be prepared

All classes a=F/M lab

For this lab the force was clearly defined and even calculated for you at the top of the data table for run 1. It is the hanging mass x g = .1 kg x 9.8N/kg ( use 9.8 for labs) =.98 N for Run 1. Force for run2 = .05 kg x 9.8 N/kg = .49 N. The slope you find from your graphs is not force, it is Ma. You were supposed to compare your slope with the force ( .98 N or .49 N depending on the run). If you found your acceleration in cm /s^2 and graphed it without dividing by 100 to get m/s^2 then you need to divide your slope by 100 to compare with the force in N since 1 N is 1 kg m/s^2 NOT 1kg cm/s^2.

Some of you found the force as if the hanging mass were 100 kg instead 100 g = .1 kg. This gives a force that is a factor of 1000 high.

Some of you found the slope and called it the force and then divided it by mass and got your acceleration. This does not prove F= Ma. It proves that Ma/M =a, something that is pretty well established .

To repeat the most important point: you must compare your slope in units of kg m/s^2 with the force ( .98N or .49N) that was accelerating the system.

Honors Practice Test

AP a =F/M Lab

The sentence just before question 5 refers to the timer tape results. Ignore this. Its from when the lab was a much longer affair.

Honors Test

Test Results

Grading them took about 6 hours between AP and Honors because I spent a lot of time trying to figure out what you were trying to do. It looks like we'll be doing some serious reviewing in most classes

Honors

One sign of maturity is taking project assignments seriously. They are even more important than worksheet or text book assignments. For those of you still in the grades before learning mode of thinking, note that project assignments count towards both homework and project grades.

Topic names and logos are overdue in many cases. Hard copies by Monday or zeroes will start show up.

Honors Momentum Schedule and Materials

Here is your new Unit 3 Schedule and two sheets

http://h1.ripway.com/DrCherdack/HonUnit3-1DMomSched10-11.doc


http://h1.ripway.com/DrCherdack/Unit5ProblemSheet.doc


http://h1.ripway.com/DrCherdack/Unit5extraproblemsr1.doc

AP Ferryman Lab

There is a fair amount of confusion about this lab so let me try to sort it out here.

We did most of the activities in class. First we had o river current. The boat crossed the river going 100.8 m in 5.04 s indicating that its velocity with respect to the water [ v b,w] was 20 m/s and in this case due north. The with the boat point straight north , i.e. heading = 0 deg, we set the current to 10 m/s. The simulation gave the x displacement as 50.4 m and the y as 100.8. The time again was 5.04 seconds. From this we calculated the total distance traveled and the speed wiht respect to the shore by dividing this distance by the time. We then calculated the velocity using velocity components of vx = 10 m/s and vy = 20 m/s.

We the tried to steer the boat so it would go straight across the river. This required that the component of vb,w in the x direction be -10 m/s . Since we knew vb,w had a magnitude of 20 m/s we could find the direction. Since the simulation reads direction as angle from north ( i.e. theta y) we could find theta x using inv cos (x component/20)and then its complement which would be theta y.

You should be able to include all this in your report and then do the additional work called for. This is all due Monday and is informal.

A purpose and conclusion are required. Did we prove or demonstrate anything ( components, relative velocity, etc.?)

Science and Engineering Fair

Here is a site about a science exhibition and and festival at the end of October.

http://www.njsciencefestival.org

AP Section 5

Several people wrote on the tests despite clear written and oral instructions to not do so. I hate to resort to such silly measures, but next time I will deduct points for tests that have been written on. Checking tests for writing is not a productive use of time and I hope you can show enough maturity in the future to allow us to dispense with this.

AP Unit 3 Schedule

This is the new schedule. It may be revised so stay posted.

http://h1.ripway.com/DrCherdack/APunit3sched%2010-11.doc


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


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


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

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

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

Honors Assignment

Your assignment for this weekend is two -fold

1) We are beginning to study momentum so read the notes and do the problems at the end. The notes give you all the information you need to answer the problems.

http://h1.ripway.com/DrCherdack/Notes%20on%20MomentumRev2.doc

2) Each student must turn in one hard copy paragraph describing in some detail their chosen topic. Do not pass around one file. Also send me your logo and name in one email per group. These are required.