AP Fluids Test Solutions

I have solutions to the test available by email request only. If you have questions about your tests these should answer them. I will not post them. If you request them you must agree not to print them and to destroy them after you have reviewed them.

Honors Review Package

http://h1.ripway.com/DrCherdack/Break%20Rev%20Pkg%2008-9.doc
Here is the package referred to in your schedule. Its longer than I would like to have assigned for the break, and many of you are already working on the alternate test and the corrections, so here's the deal:

1) Make sure you do your work and write your answers on separate sheets so you can turn in your work on the assignment but still keep the package to study from. I will post solutions Monday PM so the assignment must be turned in Monday to count

2) If you do it completely it will count as 5 homeworks toward your homework grade, but I will only increase the number of required homeworks by 2.

3)  Also, you will get 1/2 point of extra credit for every problem completed. 

4) The material covered here (not exactly the same questions) will appear on the review quiz.

5) The nuclear reaction rate sheets can wait until Wednesday

Points 2, 3 and 4 should provide plenty of incentive to do the review.

Happy New year

Note that this will take me a long time to grade so be patient.

Honors Nuclear Reaction Notes and Worksheet1

Here are important notes you must read carefully and the first worksheet

http://h1.ripway.com/DrCherdack/Reaction%20Rates.doc

http://h1.ripway.com/DrCherdack/Nuclear%20Reaction%20Rates%20WS%201.doc

TESTS!!!!

In order to keep you from forgetting all you learned up until Dec 23rd I would test you on Monday. However, since this will yield horrible results we will have quizzes in all classes on Tuesday. 

For AP it will cover all material up to, but not including fluids.

For Honors, it will cover:

 motion with acceleration in 1 and 2 dimensions; 

 electric forces and fields on charged particles, i.e. the Coulomb equation and forces and accelerations due to fields( F = QT x E and a = F/Mass); 

energy and work and relation to PE and KE in general (W = F dot delta x)net work in = delta PE + delta KE if W= O delta KE= - delta PE)....F dot delta x  means F delta x cos angle betw F and x.

electric potentials and how they relate to fields  ( delta V = - E dot delta x) and how they change energies of charged particles( delta KE = -QT delta V); 

collisions in 1 and 2 dimensions and conservation of momentum

definition of impulse ( J = F delta t) and how it changes momentum and relates to force and time. Be able to use these to find minimum  distance between two interacting particles

Staircase ( Power) Lab

Remember the three point to cover are the effect of elapsed time to accomplish the work on power, the effect of increased load on power, and the proportion of the power required for changing the KE from rest ( O KE) vs the proportion needed change the PE.  This last point should be calculated for each of the four runs.

See you all next Monday.

Honors 3 ( Period 9) Masses

FGolks,

Anthony B's mass is 73 kg and his backpack was an astonishing 18.6 kg.

Miriam's backpack was a much saner 14 lb.

Good Luck

All students

I hope all those celebrating Christmas had a good day with lots of gladness. I hope Hannukah day 4 was also a very good one. And to everyone, I hope their celebrations are filled with happiness and that you remember to show gratitude for your good fortune by helping others.

Honors Fusion Reactor Report

I have posted a report with Annexes ( European for Appendices) on the Honors Material page on my website. Its the last link on that page. Download it and go through it and find material for your group. You don't have to print it all - its pretty long.

Thermo group. Lets stick to either steam cycles or the helium cycle , your choice. You will need to learn about heat transfer, but we will focus on converting thermal ( microscopic) to mechanical ( macroscopic) energy.

Electric Power group. I will try to reform this group but don't count on it. So, in the mean time you must pursue you goal of designing a generator.

Heating group can focus on neutral beams with a sideline in current heating.

Plasma group you've got plenty of good stuff here. Focus on main issues, number of particles and how long they are confined, and the required current ( coulombs per second circulating around thetokakmak) in the plasma

Magnets group, there is a lot here but you must also find basic information about how electromagnets work.

AP Practice Free Response Questions

If you do not have the package of AP Free Response Questions, email me and I will get them to you.

Honors Collision Test

I am offering the following: Over the break take the opposite version of the test you took and I will count it as a 50 point test. Correct your test and get 25 extra credit points. You may not print out these tests you may view them on screen only.

http://h1.ripway.com/DrCherdack/HnrUnit5%20Mom%20Coll%208-09.doc

AP Fluids

I will publish a solution set to problems from the test. Do not print these, just view them on screen and make sure you understand them.

AP Unit 8 Thermodynamics

The moment you have all been waiting for..... This schedule will be reviewed and some of the problems may get revised so look for updates. Also email me if you were not in school Monday to pick up the AP Mechanics package. Also REDA the Notes on Thermodynamics (see link below). You can do the gas problems on the Rev Sheet on Fluids over the break or by Thursday 1/8 if you can resist the thrill that long.

http://h1.ripway.com/DrCherdack/APUnit8Thersched08-9.doc

http://h1.ripway.com/DrCherdack/Review%20Sheet%20on%20Fluids%20.doc


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

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


http://h1.ripway.com/DrCherdack/NotesonThermoR4.doc

http://h1.ripway.com/DrCherdack/unit%208%20problem%20sheet.doc

http://h1.ripway.com/DrCherdack/Unit%208%20extra%20problems.doc

All students

I am posting your grades on HAC today so you might want to leave town. Please remember that I only post grades for three categories and that HAC can't calculate your overall grade properly. If you are doing well in the categories you will get a good grade. If you are not doing well, try fixing it, by doing more work, getting help, or bringing in brownies.

Due to unwarranted optimism, I did not take all the files home last night, so your grades will reflect the best information I have at hand. (This is especially true for Honors Section 3-9 th period- you lucky devils) . The HAC categories will say as of last Sunday but almost all classes will reflect work handed in Tuesday or later. I'll also include latest test scores where I have them (again Section 3 Honors gets a break).

Make the best of your day off, get some rest, but also catch up on any missing work and do your next assignment. AP, look for you next schedule by 5 PM today.

Honors Schedule for Unit 6

We are plowing ahead in our investigation of the physics required for us to learn so we can design a fusion reactor. We will now look at the reactions in more detail and see what is required to make sufficient power.


http://h1.ripway.com/DrCherdack/HonorsUnit6%20NuclearReactSched08-9.doc

All Students

We have many opportunities to show kindness to others this time of year. Who we are and what, if anything, we are worth, is largely determined by what we do for others. Please take advantage on these ways to help others.

It would really great on Monday, when I ask who has contributed to one of these, if every hand went up. ...and remember, its never a good idea to disappoint a physics teacher.

The school provided a can drive and still has

1) bricks for habitat for humanity

2) packages for service personnel in Iraq and Afghanistan

3) RPO Toy drive.

All Students ( and the rest of you as well) Collisions

Momentum is conserved for all interactions elastic, partially elastic, totally inelastic, or even where energy is added, as in the case of fusion reactions or collisions with overinflated 400 kg women ( if you weren't there 9th period Tuesday you won't understand.... and its better that way).

Elastic simply means total KE before = Total KE after. Totally inelastic is often used to mean the objects stick together.

However sometimes we choose to divide the interacting objects into" the system" and the external world as a matter of convenience. In those cases the net impulse from the external forces produce a change in the total momentum of the system: delta psystem = Jnet from external sources. If a system consists of 2 objects what one loses, the other gains.

Remember direction matters backwards = - forwards and x and y must be treated separately.

Honors Problems and Solutions

a) The problem we started in class may help you study for the test. I have changed the numbers from the class example to make it more realistic

It began with a deuterium ( n,p) moving at 9 E6 m/s ( where E 6 means x 10 to the 6th) moving towards an He3 (2p,n). The He3 was moving toward the D at a speed such that the total momentum ( remember they are moving in opposite directions) was zero. Now find the velocity of the He3 and then the total KE before ( i.e. sum of KE of both particles). The fusion reaction adds an additional 3E-12 J to the KE. The fusion products that come out are a proton ( p) and a He4 (2p,2n). Find the total KE after and using the fact that total momentum is still zero find the speed of the p and the He4. mp = 1.67E-27 and mn is about the same.

b) Steam and turbine blade: The steam particle transfers 280 pods to the turbine and since it starts at 240 m/s and ends up at -40 m/s and has a mass of 1kg.

It also loses about 28000 J to the turbine blade since it s tarts with 28800 J of KE and ends with only 800 J.

c) Particle slowing down: force has x components -2E-9 N y component +1E-9 N or magnitude 2.24 at about 26 degrees above the negative x axis

d) sled total momentum is 630 N after being thrown off Anthony still has a velocity of 3 m/s forward and 195 pods of momentum. Now Ashli has 630 -195 = 435 pods and her
velocity = 435 /Mass = 435/40 = 10.875 m/s

Honors Correction

Note there is a typo in problem 3: the velocity after the collision is 0 in the x direction and 2x10 6 m/s in the y direction. Here is a link to the updated version.

http://h1.ripway.com/DrCherdack/HnrsCollMom3r1.doc

Honors Assignment

Do this one for tonight. Problem 3 should take some persistence but you can do it.

See next post. I removed the link to the worksheet with an error. The new one has better pictures too.

AP Assignments

Be prepared for Mechanics. Review Forces , Work Energy, Power, for Wednesday Section 4, Thursday Section3. Review Momentum and Circular Motion for Thursday Section 4 and Friday Section 3.

Unit 3 Extra problems Odd is due Wednesday for Section 4 and Thursday for Section 3.

http://h1.ripway.com/DrCherdack/unit_3_extraodds.doc

Unit 4 Extra problems Odd is due Thursday for Section4 and Friday for Section3.

http://h1.ripway.com/DrCherdack/unit%204%20Extra%20Problems%20OddA.doc

All Students Difference and Average etc.

Many of you still confuse delta v and vaverage. You must understand this now.

vaverage = delta x /delta t

delta t = delta x/ vaverage

if a is constant vaverage = (vf + vi)/2

delta v = vf MINUS vi

delta t = delta v/a
Also delta x does not ever = a delta t and delta t does not ever = delta x/a

Collisions

1) Many of you are still not using components correctly. In 2D problems conservation of momentum must be applied separately right from the beginning. You must put all the y components and only y momentum components in one equation and all the x equations in the other. YOU CANNOT write total momentum after at 30 degrees from the x axis= total momentum before at zero degree from the x axis (well you can write it but your equation will be untrue.)

Using one equation to find pdeuterium' and then multiplying it by cos theta will not give the right answer, especially since you don't know theta for the deuterium.

2) Many of you do not use the T-83 incorrectly: 10 to the - 11 is 1E-11 not 10E-11. The E has the "ten to the power of" built into it.

All Students Labs

Make sure your lab reports include vital data such as the mass of objects and the reference height such as h0 for the conservation of energy lab

Honors Collision Worksheet revised solns

Here are some scribbled solutions. I have not double checked them. Use them as guides to check yours. Yours should have been done neatly on separate sheets. [If you downloaded the unrevised solutions for workshhet 2 discard them]

http://h1.ripway.com/DrCherdack/CollisionWorksheet1sln.doc

http://h1.ripway.com/DrCherdack/Collision%20Worksheet%202SOLNSr1.doc

QUIZZES AP AND HONORS

AP Fluid Quiz will be Tuesday as scheduled for Section 4 and Wednesday for Section 3.

Honors Momentum and Collisions short quiz on Tuesday, longer quiz Thursday.

AP Section 4 ( Period 4)

Bring your jackets on Monday.... NO, we are not going to Brush's deli.

Honors Collision Worksheet 2

Here is the link for tonight's assignment


http://h1.ripway.com/DrCherdack/Collision%20Worksheet%202.doc

All students including Topics

1) All students should be bringing canned goods into their first period classes including my first period Topics class.

2) Please take note of the other drives going on. Most of us are so fortunate that being homeless, hungry, or even toyless (think of life without an ipod !!!) is almost beyond our conception. One way to express your gratitude for your good fortune is share it with others.

3) To those who have adopted 506 as a second place to donate food: Mr C's classes are murdering us - in terms of food brought in. If 506 is your main food drop off we've got to increase our efforts.

Topics In Physics

Some of you seem to believe that since this is an elective, homework is also elective. Please allow me to disabuse you of this misconception. Get the homework in.

Read through all the remainder of the relativity notes and start thinking of topics. You must have a topic by next Wednesday.

Honors Collision Worksheet 1

You can do this including #3. Read the notes carefully and don't quit!

http://h1.ripway.com/DrCherdack/Collision%20Worksheet%201.doc

AP Section 3

Section 3 turn your tests back in if you haven't done so already

Honors and AP labs

Because of the concert tonight:

AP Buoyancy lab, formal, due Monday both sections 3 and 4

Honors conservation of energy ( cylinder and photogate), formal, due Friday both sections 2 and 3

Honors ballistic pendulum ( sphere and catcher) informal but must show all equations in symbols and then with numbers, due Monday

AP Lab

This is the lab for this week. Please download, print, and read.

http://h1.ripway.com/DrCherdack/Archimedes%20Lab%2012-08.doc

Honors Labs

Here are lab sheets for this weeks labs

http://h1.ripway.com/DrCherdack/Lab%20on%20Del%20KE-Del%20PE12-08.doc

http://h1.ripway.com/DrCherdack/Ballistic%20Pend%20Lab12-08.doc

AP Extra credit.

Due Wednesday AP 4 Thursday AP 3. An object is 1 m high it is submerged in a barrel that is filled with a water ( density = 1000 kg/m3) for the bottom half and oil (density = 700 kg/m3) for the top half. A cube ( density = 900 kg/m3) 1 m on a side is placed in the barre and floats partly in water and partly in oil. What is the height of the top of the cube below the oil water interface? Alternatively, what fraction of the cube is in the water?

AP Gravity Equations

Everyone should be able to manipulate the equations relating force to mass of a satellite and central mass ( such as planet and sun or moon and planet) and those governing centripetal force so that any one missing quantity can be found. There should be no problem finding any quantity in these equations provided enough of the other quantities are given. Please remember that the M in Ma is for the object that is accelerating, not the object causing the acceleration.

AP Torque Lab

Better late than never ( or maybe not, you be the judge in this case). You should answer the questions in the torque lab packet. Don't worry about the triple beam if you can't remember or never knew how one works. Also, if you have case 5a data you have all the data you need for 5 b and 5c. If you have done case 6 I will count it towards extra credit, after all it is the gift giving season.

Honors Section 3 (Pd 9) Labs

In your Projectile Motion Lab: 

1) most of you stated the purpose as predicting where a marble would land. Think in broader terms: the purpose was to confirm the model and equations we use to describe projectile motion.

2) manuy of use deltas where they do not belong. It is vx or vx average that is found from deltax/delta t. It is not delta v you are finding it is simply vx.

Groups, Teams, and Seating Plans for Honors and AP

Here are the new groups (AP) and Teams (Honors).  I tried to accommodate your requests while making viable groups and teams. I may have downplayed your subject request to match you with the people you requested or vise versa. If there is something you can't live with, email me or see me after school.

P =plasma  H = heating  E= electric power   M = magnets  T = thermodynamics

http://h1.ripway.com/DrCherdack/Seating%20AP%20-3%2008-9R1.doc

http://h1.ripway.com/DrCherdack/Seating%20AP%20-4%2008-9r1.doc

http://h1.ripway.com/DrCherdack/Seating%20H-2%2008-9r1.doc

http://h1.ripway.com/DrCherdack/Seating%20H-3%2008-9r1.doc

Topics in Physics Assignment

For light from a moving forward ( approaching) source we get f =f' *sqrt[(1+v/c)/(1-v/c)]. What do you get for a backward moving ( receding) source?

Your assignment for Monday is to develop the Doppler shift for light when the light source is moving away from the detector. Show your derivation and answer and turn it in Monday. Use the same approach we used before, finding the time difference in the station frame from when the end of the light wave reaches a detector - when the beginning of the wave reaches the detector.  You can do this two ways. Keep the light source moving to the right and place the detector to the left or keep the detector to the right and have the light source move backward, to the left. Once you have this time or period T in station frame expressed in terms of the period in the light source frame, T' invert the ratio to get f in terms of f '.

AP Fluids (Unit 7) Schedule and Torque Notes

Once again, against my better judgment, we are going to do fluids before waves.

Here are the links and do read the notes. Quizzes are always possible. On the Review Sheet, you don't have to do the Gas Problems.... yet.

Also, here is the link to the Torque and Moment Notes


http://h1.ripway.com/DrCherdack/NotesonTorquerev12-30.doc

http://h1.ripway.com/DrCherdack/APUnit7Fluidsched-08-9.doc

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

http://h1.ripway.com/DrCherdack/Unit7APProbSh-05R1.doc

http://h1.ripway.com/DrCherdack/ReviewSheetFluid06.doc

Another AP Correction

Apparently the answer to problem 9 listed on the Unit 6 extra problems should be about .16 Hz or .16 per sec. It seems like the value given is for omega not f. I may actually have made that change and forgotten to go back and change the question to angular frequency instead of rotations per second.

AP Torque Notes

Having trouble with ripway this morning so see web page AP materials. The latest link on the AP materials page has some good notes on torque. Read them


The link on the AP materials page is 

documents/4bd2aeb9-9ce9-4bec-b4cf-779da049fe0c/350583-308508/downloadFile.aspx

Why the system just doesn't give the file name as the link is beyond me at this time. For a few weeks they dropped the first letter of the file names and now this. Wonder what'll happen next.

AP Section 4 Staircase Labs

I realize that this lab was supposed to be an easy one, but in all labs you should show the equations you use in your discussions. Few of you did this. Also, you were meant to include KE in your calculations of power. Furthermore, while f dot distance is a definition of Work, it is almost always more instructive to use work causes change in  KE plus change in PE in complex situations such as this one. 

For these reasons, most of the labs were in the B range, and even that was generous.

However, in the spirit of making this a recreational lab, I will only count it if it helps your grade.

AP Solution Sheets and Labs

1) Dennis has pointed out that there is an error on the solution sheet for rotational motion. In the problem where the pivot for the plank is 1 m from the end of the 7 m plank and we are looking for M2, the torque due to the mass of the plank should be taken as clockwise, i.e. as acting on the same side of the pivot as M2g.

2) For the conservation of momentum lab many section 4 reports discuss how momentum appeared to increase after some of the collisions and how friction cannot explain this since there is a gain not a loss.  Examine these cases and see if  p' includes a negative term as cart 1 bounces back after the collision. Is it because this negative term is too low due to friction on cart 1 that the momentum appears to be higher after the collision? Let me know in class or by email what you find.

Honors Sect 2 ( Period 6) assignment

Complete the calculation of change in KE for the example from class. This problem is outlined below.

Tritium ( M = 3 mp) came into collision with vx = 1,000,000 m/s vy =0. Deuterium ( M = 2mp) was at rest initially. After collision Deuterium has velocity' of 500,000 m/s at 30 deg above x axis and Tritium had vx'= 711,000 m/s and vy' of 167,000 m/s. Find out the change in total KE from before to after collision.

AP Quiz Etc

1) For homework tonight, do the advanced study assignment from the lab as well as the odd extra problems

2) Due to delays in getting to torque and equilibrium, the quiz (it has to be called a quiz now) will be on Tuesday. We will begin to work on either fluids or waves over the weekend, keep checking here for the new schedule.

AP Unit 6 Extra problems

Sorry folks, here is the link for the extra problems

http://h1.ripway.com/DrCherdack/AP%20Unit%206%20Extra%20Problems.doc

AP Unit 6 Revised Assignment for Tonight and Solns

The schedule has some errors. Please do Problem Sheets R-1 and R-2 and the odd problems from the extra problems.

You may find these helpful:


http://h1.ripway.com/DrCherdack/APRotationalSlns0001.pdf

Food Drive Etc

Folks, as you know I don't have a real 1st period class. However, we will have a food drive in 506. Please bring canned goods in. If you bring them to your first period class that's fine. If you bring them to 506 place them in the box under the desk against the side white board.

All students Study Groups

I am open to requests for study groups. Since the groups should represent a balance of skills and personalities I will not necessarily honor requests, but I will consider them. E mail me with your requests.

AP Study Group Report

I heard enough whining to convince me to relent on the Unit 5 meeting and report for AP students. AP only start with unit 6

AP Centrpetal Lab corrections for Msg

Here is a link to discussion as to why you can ignore the correction for the fact that there is a vertical component of FT and how to calculate the true Fc and Mstopper omega sqrd r if you don't ignore it.

http://h1.ripway.com/DrCherdack/centrpetal%20correction.doc

Honors Unit 5 Schedule

Here is the new schedule and a problem for tonight. NOTE Assignment for this weekend is The Unit 5 Worksheet 1r1 not Prob Sheet. Momentum Worksheet M is for Monday night

Tonight's problem is:

1) For a totally elastic collision, use the equations we developed yesterday and today (see earlier post today) to find v1' and v2' given v1 = 1 m/s v2 = -1 m/s and m1 = 1 kg m2 =0.5 kg.

2) Do this again only use the masses and v1 and v2 from the last run ( row 12) of our momentum lab. See how far off your results are from the lab and see how much KE was lost during the real collision. use (MAv1sqrd/2 + MB v2 sqrd/2) - MBv2'sqrd/2 since v1' =0

http://h1.ripway.com/DrCherdack/HonorsUnit5Mom%20colsSched08-9.doc


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

http://h1.ripway.com/DrCherdack/Unit5Worksheet1r1.doc

http://h1.ripway.com/DrCherdack/Unit5HnrsProblemSheet.doc

Honors Elastic Collisions

As promised here is the derivation. Stay tuned for some problems in collisions and momentum.


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

All students including Topics in Physics

Study groups must meet at least once for one hour outside class per unit and every student must turn in a report covering where, when, who, and what was discussed. THIS IS A REQUIREMENT even for TOPICS.AP owes reports for Unit 5 and 6. Honors just for momentum and collisions.