# Homework

• 5-22-19

Today, we had the opportunity to go over the FRQ solutions to the recent 2019 AP exam.

Here are the video explanations for the 2019 FRQ questions.

5-1-19

We have just taken our AP class final exam. This grade will go toward the 4th quarter and for the 2nd semester. Your job now is to prepare for the AP Exam on Tuesday.

4-2-19

After our quiz on Diagnostic Test #3, we will begin practice taking actual AP Exams in class. (If you have an AP Exam Prep Book, you should be taking those practice tests at home  as well.) The idea is to practice taking lots of questions without fussing too much on any individual "stupid/vague" questions. It's a good time to not only review and refresh content, but also practice efficient test-taking strategies.

Here is a valuable Khan Academy Link to a complete review of AP Physics Part 1 and video solutions to the 2015 practice test FRQs you are now working on.

Homework: View this Khan video on Torque & Angular Momentum, as there will be a few of these concepts tested on the AP Exam. Also finish the essays on today's 2015 practice exam. Next class, we will work on the 2016 practice exam.

3-27-19

We worked on Diagnostic Test #2. Ignore questions covering things I did not cover in class.

Next class, I will give you a quiz with 5 selected questions from today's Diagnostic Test #2.

Diagnostic Test #2

3-25-19

Time now for a few diagnostic tests and then some practice tests to prepare for the exam.

Take the following Diagnostic MC Test 1 to see which areas you are weak in and strong in. This will help focus your study. The answers are given at the end, indicating which major topic the question came from, followed by complete step-by-step solutions to all of the problems. Be effective with your time. Work together if you like. Do you have to do all of them? No. But the more you do, the better you'll prepare. Counts as a homework grade for doing a chunk of it. But don't do it for me...Do it for you.

3-21-19

Lab: Wheatstone Bridge

Test Ch 20 Circuits next class (Monday). Focus is on electric circuits and VIRP charts.

Then we are ready to do practice tests to prepare for the AP exam.

3-15-19

Today, I checked the Ch 20 homework and showed 2 videos (Electric Fields, The Battery). Next class, I will check the Ch 20 homework problems of those students who were not here today.

Homework: Read your Ch 20 Study Guide pdf section on how to analyze VIR charts. Then solve the VIRP FRQ (P stands for Power) and try to understand the solution provided. I will go over it in class and we'll do a few more. Then that will complete chapter 20. One more lab, test on Ch 20, and we will start reviewing for the AP Exam.

3-13-19

We are on our last chapter (20) on electric circuits.

C&J textbook Ch 20 pdf

Ch 20 Lecture Slides

Ch 20 Study Guide

Lab: Wheatstone Bridge

Homework:

Read Ch 20 sections 20.1---> 20.7

Do probs 1, 3, 8, 10, 12, 14, 22, 26, 40, 43, 49 (Answers are in Stuy Guide)

3-8-19

After a quiz on a sphere suspended by a thread at an angle in an electric field, we practiced an FRQ on finding the net force on a charge affected by 2 other charged particles in an electric field (similar to C&J prob 16. Then we solved another FRQ involving an electron shooting through an electric field between 2 charged parallel plates.

The test next class is only on Ch 18 Electrostatics. It has some MC questions and 2 or 3 FRQs.

3-1-19

Today, we discusssed the solution to the lab report's FRQ question on standing waves created by a string oscillator (Starts at 22 min). Then I gave a demonstration on static electricity, followed by a lecture on induction vs. conduction, along with explaining the uses of an electroscope. I compared Coulomb's law with the Law of Universal Gravitation and noted that they were both examples of the Inverse-square Law. Tonight, you will do problems dealing with Coulomb's law and the Electric Field.

C&J Textbook Ch 18 pdf

Lecture slides for C&J Ch 18

Official Homework Solutions

Detailed Solutions for Ch 18 # 4, 15, 16, 30, 31, *40, 61, *68, **71

C&J Ch 18 Study Packet

Homework:

Read Sections:  18.1 Origin of Electricity

18.2  Charged Objects & Electric Forces

18.3  Conductors & Insulators

18.4  Charging by Contact & Induction

18.5  Coulomb’s Law

Do Probs # 4, 7, 11, **25

18.6  Electric Field

18.7 Electric Field Lines

Do Probs # 30, 31, 33, *39

18.10  Printers & Copiers (Practical Applications of Static                                                                                     Charges)

2-27-19

Today we did a lab on the vibration of a string. We used the speed-of-a-wave-on-a-string equation, and the universal wave equation to determine the frequency of the string oscillator. I assigned the FRQs at the end of the lab packet as homework.

Lab: Frequency of a String Oscillator: Waves on a Taut String

2-14-19

C&J Ch 16 & 17 Lecture Slides

Homework

Read  "5 Steps to a 5" Waves & Simple Harmonic Motion and do Practice Problems 2, 3, 4, 5.

Read thC&J CH 16 & 17 Study Guide on Speed of a Wave on a String Equation, Doppler Effect, and Harmonics.

LAB: Waves on a Taut String

(The "5-Steps-to-a-5" Waves & SHM reading assignment above supplants the C&J CH 16 & 17 content below. It efficiently targets the content of both of those chapters.)

OPTIONAL:

C&J Textbook Ch 16 (pdf)

Read C&J 16.3 (Speed of Waves on Taut String and do probs 14, 15, 16, 18

Read C&J 16.6 (Speed of Sound)

Read C&J 16.10 (Doppler Effect)

Read C&J Textbook Ch 17.1 and 7.2 (Wave Interference, Beats)

2-12-19

Homework C&J Chapter 10

Do effective-spring-constant problems # *31, *32,

Read Section 10.5 on SHM and do probs 47, 48, 49, 51, 52, 54, *57

Extra simple pendulum problems # 63, 64,, 65, 66

Test Thursday: 2 FRQs on Ch 10

LAB: Simple Harmonic Oscillation Determination of K.

1-25-19

We did a lab that resulted in our experimental discovery of 2 important equations in Ch 10 regarding force & stretch and stretch and PE stored in a spring. Now it's time to practice these concepts in Ch 10.

Textbook pdf for Ch 10 Springs & Simple Harmonic Motion

Lecture Slides for Ch 10

Homework Solutions for Ch 10

Study Guide for Ch 10

Homework: Probs C&J Ch 10 # 23, 24, 25, 26, 27, 28, 29, *30

1-16-19

We worked on the following problems in our study packet for Ch 9:

10.22 boom

10.11 beam suspended with ropes

1220-N boom

old door 3 m high

10.44 uniform door

Lab next Fri B2 and an opportunity to ask me questions.

Test next Fri Rotating B2 on Ch 9 (mostly).

1-8-19

Homework: Do Ch 7 probs 22, 25, 26, 27.

1-4-19

After a quick lecture on CH 9 Torques, we worked on Problem # 17 (cafeteria tray). If you didn't finish Prob 17 in class, finish it at home and be prepared to ask me for help if stuck. Next class, we will do ladder problems like #22.

C&J Ch 9 Torques Study Packet

C&J Ch 9 Torques TEXTBOOK

C&J Ch 9 Homework Questions & Answers

12-21-18

Today we had a cumulative Ch 7 test for some physics closure and diagnostic assessment of our current grasp of essential concepts. There is no homework over the break for those who were here today. For those of you who were absent, I recommend you take the test on your own for practice and to check your current level of understanding. (This is for you, not me. No need to hand anything in.)

The second test question about the hanging climber rope tension threw most of you, so I called it a bonus question. If you treat it like an inclined plane problem, the solution path becomes clear.

Ch 7 Cumulative Test

Ch 7 Cumulative Test with complete solutions

12-11-18

Today we discussed whether or not KE is conserved during collisions. Discussed ballistic pendulum problems, 2-D problems like the Coal & Cart *38 prob.

HW: Ch 7b Probs 18, 19, 26, 27, 28, 29

12-7-18

Test Ch 6 (mostly)

HW: Read Ch 7.1 IMPULSE-MOMENTUM THEOREM and do probs 1, 4, 5, 6, *10

Read Ch 7.2 CONSERVATION OF LINEAR MOMENTUM and do probs 16, 17

pdf of C&J Ch 7 Momentum

Selected handwritten answers to selected problems

Official typed answers to selected problems

Ch 7 Resource Learning Packet

12-5-19

Review for Ch 6 (with some of Ch 5). MC Questions & FRQs. Test Friday.

11-29-18

Discussed problems *42 (ball-on-a-slide), *44 (water slide), **83 (toy car loop)

Homework: C&J Ch 6 probs 35 (water-skier jump), 43 (skier, dip, and hill)

11-27-18

Read/Study the appropriate C&J textbook sections to solve Problems Ch 6b:
6.5 Conservation of Mechanical Energy # 33, 35, 37, 39
6.7 Power # 59, 61
6.9 Work Done by a Variable Force # 69

11-20-18

Test Ch 5 (mostly)  This test will include some FRQ content from Ch 3 (projectile motion) and Ch 4 (F=ma). The test will include more FRQs and some may be more challenging in nature than in the past. You are at the point now where you should quickly solve some of the problem types that you have seen before, without spending too much time trying to figure them out. Practicing working quickly will help you finish the actual AP Exam in the allotted time.

Homework:

Read the Ch 6 sections listed and do the associated problems indicated.

Problems Ch 6

6.1 Work # 1, 3, 5, 7

6.2 Work-Energy theorem & KE # 13, 15

6.3 GPE # 27, 31

Lecture slides for Ch 6 Energy

pdf file of C&J Ch 6 Energy

Official Solutions to the homework problems

Ch 6 Review packet/study guide

11-16-18

Because of the pep rally, class is only 73 minutes long today.

Today, we discussed strategies of solving vertical-circle problems like 37, 39, 41, 40. It is important to know the location of the object in the vertical circle, since the normal force and weight contributions to centripetal force depend on these locations.

We also discussed "bug-on-a-record" problems like 17, 18, 50

Solution to Complicated Banked Circular Track problem

Test Ch 5 (mostly) next class Tues, November 20. This test will include some FRQ content from Ch 3 (projectile motion) and Ch 4 (F=ma). The test will include more FRQs and some may be more challenging in nature than in the past. You are at the point now where you should quickly solve some of the problem types that you have seen before, without spending too much time trying to figure them out. Practicing working quickly will help you finish the actual AP Exam in the allotted time.

11-14-18

Because of parent conferences, class is only about 45 minutes long today.

In-class discussion of satellite problems 27, 2831, 33 . Remember that satellite problems usually have you relate the centripetal force equation with the Law of Universal Gravitation equation. This makes sense, since the centripetal force is created by the gravitational force of attraction between the satellite and the planet.

Test Ch 5 (mostly) Tues, November 20.

Homework: Ch 5 probs 50, **58

Complete Book Solutions to Ch 5 Problems

11-5-18

Analized prob 19 swing carnival ride

Homework C&J Ch 5 probs 21, 22, 23, 24, 25

11-1-18

Homework: Read C&J Chapter 5.1 --->5.3 and do problems 1, 2, 5, 7, 11, 13, 14, 15, 16. Here are the Homework Solutions. Here is are my Ch 5 lecture slides to give you a preview of what I will be talking about.

10-26-18

We went over the homework problems, emphasizing that a correctly-labeled free-body diagram (FBD) provides the conceptual basis from which the needed equations are derived. Some of you expressed a bit of frustration that not all of the solutions were provided. Here are the official solutions to C&J Ch 4 problems 1 thru 66. Here are the C&J Ch 4 solutions 67 thru 117.

As for the question Sam raised at the end of class, it is only true that Fk = mg sin Θ if the moving system is in a state of dynamic equilibrium (no acceleration) where the applied force moving the object along the plane (mg sin Θ) is opposite and equal to the frictional force Fk. However, in problem 80 that I was explaining, the object is accelerating (non-equilibrium condition) and it is the rope tension which supplies the applied force, not the weight component (mg sin Θ), resulting in the oppositional force Fk.

Homework: C&J Ch4 probs **88, 94, 97, *105, *107, *108

Test Ch4 (mostly) Thurs Nov 1

10-24-18

Today we went over the homework problems on the whiteboard. Emphasis was placed on the correct way to draw and interpret free-body diagrams as a foundation for deciding how to solve a problem. Then we did problem 33 in the learning packet.

Next class, we will tackle 2-body tension problems along an inclined plane and how to solve these problems a different way using the Universal Axis Method. We will also see how Atwood Problems are simply a varation of a theme (concept). Finally, we will see how the U.A.M greatly simplifies the solution of a 3-body tension problem.

Homework: C&J Ch 4 # 60, **65, 73, 75, 76, *80, *82

Test Ch4 (mostly) Thurs Nov 1

10-22-18

Today we did a lab activity which experimentally shows that tan Θ =µ. This also introduced us to the analysis of an object moving (or not moving) on an inclined plane with a consideration of how vectors emanating from said block are identified. We then discussed the analysis of a 2-body tension system, moving with a common acceleration.

Homework: C&J Ch 4 probs #

52  tightrope walker

55  helicopter at constant speed

57  sled pull from an angle at constant velocity

*61  hanging sign

*62  2-body tension at rest

70  2-body tension with acceleration

71  elevator problem

C&J Ch 4 Lecture Slides

C&J Ch 4 Learning Packet

Solutions to HW Problems

10-18-18

Today we went over the recent test and finished up the previously-assigned homework in class. Then we had a "quiz" on the chandelier problem, an example of static equilibrium, to gain practice in drawing correctly-labeled vectors emanating from a free-body diagram, in order to visualize the relevant forces involved.

Homework:        Problems:

4.8 Normal Force & Apparent Weight

# 36, 37

4.9 Static & Kinetic Friction

# 41, 42

10-16-18

Homework:                 4.3 Newton’s Second Law and Free-Body-Diagrams (FBD)

# 1, 3, 5, 6,

4.4 Vector Nature of Second Law

4.5 Newton’s Third Law

# 11, 15, *16, *17

4.6 Law of Universal Gravitation

4.7 Weight

# 19, 21

The end-of-Ch4 problems are found in C&J Ch4.10 ---> 4.12. Since, I forgot to post these HW problems, you may work on them in class. Here are the solutions to the problems as a pdf file.

C & J Ch 4 Lecture Slides

During rotating block, we investigated the relationship between friction and normal force. We found that the ratio of friction force to normal force is the very definition of the coefficient of friction, µ.

10-10-18

We went over problems 31, *36, *37 and another baseball player and bleachers problem.

Test this Friday Ch 3 (mostly).

10-5-18

Checked Homework and solved # 40 on the whiteboard. Did Chapter 3 #35 in class (solution is in your StudyGuide). Did the StudyGuide "baseball problem" and "falling meteor" problem.

Homework: Read C&J Ch 3.4 on Relative Velocity.  Do Problems 29, 31, *33, *37, *39, *41, 49, 53, 61

Test Friday 10-12-18 mostly on Ch 3.

10-3-18

Continued discussion of horizontal projectiles. Lab Activity: Determining the Horizontally Launched Velocity of a Projectile. Handed out C&J Ch 3 StudyGuide.

Homework: Read C&J 3.1 ---> 3.3  Then do C&J Probs 3, 5, 11, 17, 23, 25, 40. Be prepared to be called upon to explain any of these problems to the class or do one on a pop quiz.

9-27-18

Reviewed for the test by doing the following practice questions: Ch 2 # *53 Raft Problem, *77 Floating Log, *51 Falling Cement Block, 68 Rifle Bullet

Demos: Constancy of speed along horizontal axis, Simultanaiety of x and y components for projectiles

Lectured (Ch3) on calculation of impact velocities for horizontally-launched projectiles

Test Ch2 next Monday.

9-25-18

Reviewed and applied the 3 kinematic equations. Alalyzed the graphs of a pendulum half-cycle swing to explore the relationship between velocity and acceleration during the swing.

Test Ch2 next Monday.

9-21-18

HW: Read C & J Ch 2.6 ---> 2.7  Do problems # *29 (segment problem), 37, 43, 44, 45, **57 (segment problem)

Ch 2 Lecture Slides

9-19-18

We finished the Cart & Ramp lab: Motion with Increasing Speed and learned the significance of the graph slopes depending on the units of what the rise and run units are.

We were not surprised by the distance vs. time graph shape of the Chain Lab, and we are anxious to see if the chain's speed vs. time graph reflects our expectation!

Homework: Read C& J Chapter 2 Sections 2.1 ---> 2.5  Do Problems # 3, *7, 11, 13, 19, 23

HW solutions written out

HW solutions official typed

Ch 2 Study Packet

9-11-18

We went over the homework problems # 44 and 46. Introduced the concept of the equilibrant used in problem**67. Did problem # *18 and 19 (NaCl) to show how a 3-D problem can be broken down into separate 2-D problems. Talked about the strategy for solving the easy car-pull problem #30. Test on Ch1 Vectors and dimensional analysis next class (14 MC and 2FRQs). Homework is to solve problems # *29 (beach ball), # **53(sailboat race) and # *65 (wandering bear).

9-6-18

Do C&J Chapter 1 Intro to Vectors Problems 44 and 46 on page 26.

We'll go over the homework next Tues, with a test on Thursday.