Last Call Honors Period 6 Last week's test

Please turn in your tests from last week tomorrow. I may have adjust your grade upward. I can't do it unless I have your test.

Real AP LAb Link

Since the a=F/M lab was a nightmare to grade I certainly don't mean for you to do it again.

Here is the correct link

http://h1.ripway.com/DrCherdack/Lab%20on%20Delta%20PE%20mv22gate.doc

AP Labs

1) Save your labs because colleges might want to review them before granting credit.

2) You'll love this one . We'll do it Wednesday and Friday.

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

Lab Reports

I am operating under the increasingly difficult to maintain supposition that you don't do this just to drive me nuts.  That it really is due to your lack of facility with graphs, not perverse senses of humor.

I have just gone through 9 resubmittals of the a=F/M labs. Lots of errors were cleared up, but SIX of them still failed to compare the numerical value of the slope for the 100 g series to .98N or the slope for the 50 gram series to .49N. Several did make reference to individual points and how they showed a/(1/M) was close to F, some did mention that the acceleration did decrease as Mcart went up, some did calculate the slope somewhere, but you all mentioned that the slope should equal the force and then  6 of you failed to find out if it did. Some scientists you are; weren't you even curious?

The reason for using the slope is because a best fit line represents data from several trials so  this best fit line, which averages out random errors of individual runs, tends to give more indicative results. Also using the slope can remove some constant systematic errors like those caused by friction in the pulley.

In any case I believe I told most of you what you should do in my comments or orally, so next time make sure your read the relevant notes, try to remember what I tell you and check the blog posts as well.

AP and Honors Students

Try going to my OnCourse website and go to the Honors Material page and look over Notes on Energy Fundamental. A good review for honors and not a bad overview for AP.

Honors Unit 4 Schedule

If you downloaded the Unit 4 Schedule before 10:25 this morning you got the wrong version. Please download it again.

Also the link to the RM worksheet is not working, I'll fix it before you need it.

Honors Unit 4 Schedule

Here is the schedule for a unit where we will study motion in 2 dimensions and also review electric force and energy. Note we will have a second test on electric force and energy on Thursday.

Here is the problem mentioned in the schedule as due tomorrow:

Find the potential energy when a deuterium (D) nucleus ( one p and one n) is at a distance of 5x10-15 m from tritium (T) nucleus ( one p and two n). Would the D nucleus have to start with the much KE. Find the field strength in device that would give the D nucleus the required KE if the field is applied over a distance of .25 m.

http://h1.ripway.com/DrCherdack/Hon%20Unit%2042D%20Mot%20Sched08-9.doc

http://h1.ripway.com/DrCherdack/Unit10Worksheet2.doc

http://h1.ripway.com/DrCherdack/Unit10Worksheet3.doc

http://h1.ripway.com/DrCherdack/Unit11Worksheet1.doc

http://h1.ripway.com/DrCherdack/Relative%20Motion%20WS%20RM10-08.dochttp://h1.ripway.com/DrCherdack/Unit_2_worksheet_1.doc

http://h1.ripway.com/DrCherdack/Unit_2_Worksheet_2_.doc

Honors Unit 3 Test Results

The results of the honors quiz were not bad for 6th period and were not quite as good the results for the 9th period class. However, considering the quality of the students in the class, the results on the whole indicate that you had not had enough time to digest the several new concepts involved. Also some more practice in dealing with the concepts and terminology of electric fields and potential is clearly needed.

Therefore this test will be used as an assessment of where we were on Thursday not a judgment of your ultimate mastery of the subject. In other words don't sweat about its effect on your grade, relax and learn.

Honors Next Unit

Check here by Sunday Morning for the next unit. I am still pondering whether to move to two dimensional motion; collisions; or magnetic forces. Stay tuned for the exciting outcome.

We will revisit electric force and potential soon, so let it simmer on the back burner of your brain for a while.

AP Unit 3 Test

All those who received a score below 86 will be eligible for a makeup test next Thursday - not in class time. Sign up for it in the black book by Tuesday. It will replace your grade with up to an 86. I will use it and not the higher of the two so make sure you are prepared.

AP Unit 3 Test

Please turn in your Unit 3 tests Monday. I want to lower all your scores so you don't get swell heads. Actually I want to check and make sure I didn't take off points by looking at the wrong one of my answer sheets while rushing to get your results back to you.

HOnors Section 2 ( 6th Period)

Folks I owe about half of you a pretty big apology. I did use an electron as QTest in problem 2 in one version. In my hurry to get the tests back to you, I may have made some other error so Please return ALL Unit 3 tests on Monday.

Honors Assignment

Your assignment for tonight, due tomorrow, Friday 10/24 is:

1) Finish the lab which should have been done by yesterday or today but I'll let that go for now. Its just fill out the form plus a purpose and conclusion ( not a movie review on how much you enjoyed it)

2) Think about today's quiz and come in with two problems you would like to know how to do.

APSchedule for Unit 4 Work and Energy

Here it is:

http://h1.ripway.com/DrCherdack/AP%20unit%204%20Energysched-08-9.doc

http://h1.ripway.com/DrCherdack/unit4ProblemSheet.doc

http://h1.ripway.com/DrCherdack/Unit4worksheet1.doc

http://h1.ripway.com/DrCherdack/Unit4worksheet2.doc

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

AP Ramp Quiz

Today's ramp quiz will not be an important factor in your grade, but it should alert you to the need to understand the physics and be able to present the physics in equation form rather than just crank through numbers using remembered patterns to get answers to numerical problems.

Honors Retest

Those who received a score (NOT A GRADE) of less than 76 on the last test can have a retest on Wednesday. It must be out of class hours; you must have all your Unit 2 Homework done by end of school  Tuesday; and you must sign up for it by class time Tuesday.

AP Components Lab

I was surprised to see that there is still some confusion over purpose of labs. Remember that they are parts of the scientific method. Their purpose is to confirm hypotheses. In this case the  first hypothesis was that the parallel component of the force of gravity on the cart was 

Mcart g  cos of the angle between the ramp and direction of gravity. This cos was simply h/L. 

The second hypothesis was that the perpendicular component of the force of gravity was equal to

Mcart g cos of angle between the perpendicular to the ramp and the direction of gravity. Note that this angle is the complement of the first angle and its cos  

= sqrt( 1 -(h/Lsquared)..

the third hypothesis is that acceleration parallel to the ramp = Fparallel/Mcart

The purpose was to confirm these by

1) predicted Fparallel using the equation from above and then measure the force it would take from the hanging weight to balance or cancel the component of gravity pulling the cart down the ramp. In other words did Mcart g h/L = Mhanging g ?  

Obviously, one needed to record the  h, the L, the predicted Fg parallel, and M hanging to accomplish this purpose.

Similarly, predictions and measurements should have been made and recorded for Fg perp and for a parallel.

All this should have been done for each of the three elevations ( angles). All quantities and all calculations should be included in your lab reports as well as purpose and conclusions.  In view of the fact that this somehow may not have been apparent to you despite our review of the a=F/M Lab, I will give 5 points of extra for every correct lab that comes in tomorrow and will not include any penalty on labs coming Tuesday.

All Students etc

I just got this from Ms. Bowden Please read and consider.

Hoboken Cares, a volunteer project based organization, is currently collecting "gently used" sneakers for children and adults in Jamaica. Many of the children & adults are mentally and/or physically handicapped and some are innocent young children born with HIV/AIDS.

I will have a bag/box in room 412 for all donations. The due date is November 5th. Please spread the word!

Keep in mind--- your sneakers will be the FIRST pair they EVER own!

AP Lab

Here is the lab sheet for the lab we will do on components of force. Note the actual lab performance will differ a bit from the write up

http://h1.ripway.com/DrCherdack/normal%20perp%20labwphotgatesR2.doc

Honors Test

If you have the last test in your possesion including answer or question sheet or both, turn them in immediately

AP Quiz

There was an error in the way I wrote question 4 on your last quiz. Two answers can be correct. If you had question 4 marked wrong return your test for gegrading

All Students Browsers

If you have trouble reading or downloading using the Microsoft Bowser, try downloading Firefox and using that as as your default browser. Also consider using Safari as an alternative.

Grades

Your grades were just updated for material handed in by 10/13. Thus there is some new stuff that is not entered yet.

Also, only look at the three categories not the total grade. There are very many labs outstanding in need of repair. I did not include these in your lab average, but if they are not fixed by Monday they will get low or zero grades, so clear up your errors for once and for all.

Honors Schedule

Managed to get this done so here it is.

NOTE worksheet Assignment for the weekend is Worksheet 1 Not 3

http://h1.ripway.com/DrCherdack/HonorsUnit3ElecStat-08-9.doc


http://h1.ripway.com/DrCherdack/Unit10Worksheet1.doc

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

AP Unit 3

I believe this is the missing link. NO not the one between ape and man. The one for units extra problems.

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

These are the one you were to do in class last Wednesday but we had the quiz instead. Do 1-6 by Thursday

Techxplore team

Techxplore team members please attend a brief organizational meeting at 2:30  Wednesday afternoon in 506

Lab Data

Bring lab data for any lab you want to do or redo for labs. We'll be learning how to use a spreadsheet to help make calculations and graphs.

Honors Math Review

Her are some quick problems due Monday. You won't get extra credit for getting 9 right but you may make some big bucks in Vegas if you do.

Math Review Honors 10-11-08

In the southern hemispheric country of Upsidownia, penguins are strictly regulated. Each bunch must contain 12 penguins. A flock contains 144 penguins, but a gaggle contains 36 penguins. Penguins can circulate to or from any flock or any gaggle or any bunch.


1. Two flocks and three gaggles converge on an ice floe. They can reconfigure themselves into how many bunches?

2. Six bunches and two flocks land on a beach. They can combine into how many gaggles?

3. Eight bunches and two flocks are swimming in a bay. Seals eat two gaggles of them. How many bunches are left?

4. A bunch eats 12 kg of herring a day. How many kg of herring do two gaggles eat in a week?

The force between two charged particles, with charges Q1 and Q2 on them, is given by (this is real by the way)

F= 9,000,000,000 Q1 x Q2/ r squared; where r is the distance between them.

Charge Qa is 4 m from Qb. The force between charge Qa and Qb is 12 N.

5. If the distance is increased to 8 m what is now the force.

6. If the distance increased to 12 m, what is the force?

7. If the distance is decreased to 2 m what is the force?

8. If the distance returns to 4m  and Qa is doubled and Qb is tripled what is the force?

9. If Qa is doubled from its original value and Qb is halved and the distance is tripled, when will the Mets win the World Series again?

Techxplore competition

We will  (try to) compete in the Techxplore competition which is described  at the following site:

http://www.nstep-online.org/techxplore/default.asp  (not  a live link)

All we need is a few good men ( girls are you going to take this sexist remark lying down? _ Make sure I hear from you too) to bring glory to ourselves and the school - or at least have some fun and learn some stuff trying.

Contact me ASAP if you are interested.

Honors Physics Math Concepts Assignment

Write a concise definition or description of what each of the following mean:

Adding A to B

Subtracting A from B

Multiplying A x B

Dividing A by B

The ratio of A to B

Raising B to the power of A

How do you find the change or difference between two numbers?

How do you find the average of two numbers?


Be prepared to discuss all these in class Friday

a =F/Mass Labs

I am sure many of you are confused about the graphing for this lab so here is some clarification

1) Your horizontal axis really is  1/mass.  The scale should run from zero to about 1.7. The units should be (1/kg). The trial with the greatest mass, probably about 2.1 kg, is your first point. It should be plotted at about .47 for the horizontal coordinate. With luck it will be about .46 m/s2 for  the vertical coordinate.  The last point should be your lightest run. Its horizontal coord should be about 1.67 (1/kg) and the vertical coord should be about 1.6 m/s2. Note that you may have your acceleration in cm/s2. Too convert this  to m/s2  simply divide by 100.

2) Only for those who have spark tape data. 

For the tape data just do  a plot of the tape data  as a position vs time graph. 

I am afraid that the tape may have spoiled you first run. If it did, treat the first run as bad data and don't try to fit that point in your best fit line graph of a vs 1/m.

All Students Room Changes for Wednesday 10/8

To accommodate an inservice seminar in room 506 on Wednesday the following room assignments have been made:

Period 1 408

Period 2 408

Period 3 412

Period 3 412

Period 7 408

Period 8 412

Period 9 414

Students should report to PE for lab periods. My students will receive their quizzes in these rooms.

AP Extra Credit Solution

Here are two solutions to finding the theta required for a given delta x and delta y  and initial speed.   Mine starts with the ratio of x and y, and Charles begins with  an equation for x.

The second part of my solution owes itself to Charles' reminding me that 1/(cos squared)

 = tan squared plus 1. Thanks to this we both end up with an explicit equation for tan theta from which you can find theta.

http://h1.ripway.com/DrCherdack/Theta%20by%20Charles.doc

http://h1.ripway.com/DrCherdack/Theta%20GeneralSoln.doc

All Students

I have heard that many of you have three tests tomorrow. Therefore we will have our quizzes on Wednesday, even though I will not be in the classroom on those days.

AP Ferryman Lab

This lab is informal ( see your course guide) and since we sort of completed it Friday it is due Tuesday.

Make sure you did read the a=F/M lab.

All students: More good news

On Wednesday 10/8 I will be attending a a day long session on introducing engineering into a physics course. Therefore, you will once again be doing worksheets instead of having to deal with me. AP worksheets are contained in an earlier post. Honors will be posted on this blog Monday.

AP Extra Credit Opportunities

Put on separate paper from homework and mark clearly: extra credit. Due by Monday

For projectile motion

1. Prove that 45 deg is the angle giving the longest range if delta y is zero. A real proof not just 45 is in the middle. (10 pts)

2. Prove that range is the same for 30 and 60 deg if delta y y is zero ( 5 pts)

3. Find the equation for angle given delta x delta y and vi. Note the equation should yield two solutions some of the time and not solutions if delta y or delta x are too great for a given vi. Find means derive, not look it up!

AP Text Solutions

Here are solutions to some homework problems from your book

http://h1.ripway.com/DrCherdack/Solutions%20to%20Chapter%203%20Se.doc

Also problem 24 is just adding vectors: the wind has both east and north components which must be added to teh plane's 300 m/s . My recollection is final values are 387m/s east 50 m/s north.

Use Pythagoras and inverse tan to find magnitude and direction

AP Urgent.

Due to repeated failures of oncourse I am now posting links directly in my blog. Email me if you have any problems

Here are schedule, Ferryman lab to be done by Monday, labs for next week, Honors worksheet and extra problems for in class Wednesday, and sheets for homework and some extra sheets if you want to practice.

http://h1.ripway.com/DrCherdack/APunit3sched%2008-9.doc

http://h1.ripway.com/DrCherdack/ferryman%2010-08.doc

http://h1.ripway.com/DrCherdack/WorksheetF-2Hnr.doc

http://h1.ripway.com/DrCherdack/Unit3problemsheet.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/Lab%20on%20a%20=F%20divided%20bym%20AP.doc

AP Labs for Section 3

I need to see the Projectile Motion( Shooting for an A) Lab Reports from Christine, Jack, Patrick, Howard, and Ben. Please bring them in Monday.

AP Students

The Unit 3 Schedule Worksheets and labs will be posted by about 4:30 today so check AP materials and homework/events at my oncourse website.

All Students

Please check the out folders regularly. It's not very rewarding to spend time grading labs and see them sit in the folders for days on end.

Research Topics

Cool video http://www.asterpix.com/console/?as=1187646801883-e57383c789

Honors Sect 3 (9th pd)

After revieiwng your labs I have concluded that we are not yet where we need to be. Bring in yourtapes and data and all else from the constant velocity and free fall labs. Its what we'll do tomorrow.

Lab Resubmissions and See Me s

If you  a "resubmit" on a lab., make the corrections in a neat and orderly way. Often the best way is to edit your word processor document and turn in the new copy. Sometimes you can hand write in corrections or additions. This is true for some graphs and equations. This must be done neatly. In all cases write resubmittal on the top and fold in the original report if you are submitting a new one. This should be done within 3 days of getting the original back.

The same applies to labs  " see me" grades, although you must of course see me before resubmitting, unless I announce that I will address the issues with the whole class.