Homework

In addition to webassign homework, I will assign and suggest problems for study groups to work on.

For the group quiz bonus, each person should log their time with their study group (in that Google spreadsheet you used to sign up for groups), and then hand in any assigned problems. Just hand in *one* writeup of any assigned problems. Groups should rotate among group members who writes up the assigned problem.

Problems are from the Study Guide unless otherwise noted.

[34] Lenses / Mirrors / Optical instruments

Assigned- Write up Young & Freedman problem 34.51: "A...camera has a standard lens with focal length 50 mm and can focus..."

Suggested- Ch 34 of SG:
TF 1,2,3,5,7,8,9,10,11,14,15,16,17,18,20,23 (Pick a few)
Q 2,4,7,10,13
P 1,9,12

[32] E & M waves [33] Reflection & Refraction

Assigned-: Write up Problem 8 (Chapter 33) in the study guide.

Suggested- Ch 33 of SG:
TF 1,3,5,6,13
Q&A 1,9
P 3,7,8

[30] Inductance & [31] Alternating current

Assigned- Discuss, and then write up discussion question Q30.1 in Young's textbook: "In an electric trolley or bus system...." Think of the circuit through which current flows from the power plant to the bus and back again as one big current loop with a lot of current flowing in the loop. Now, imagine that you have a knife switch that you suddenly open, such that the current drops to zero very fast. Say what happens to the magnetic flux in the loop (in terms of the rate of change of the flux), and what that in turn implies...

Suggested- Ch 31 of SG:
T/F 1,2,5,17
Q&A 2
Probs 11

[29] EM Induction

Assigned- Problems 1 and 2 below (SG ch 30)

Suggested- Ch 30 of SG:
T/F 1,2,4,5,6
Q&A 1
Probs 1,2,3,4

[28] Sources of magnetic fields

Assigned- Writeup (with sketches) SG Problem 3 (one of the suggested ones below).

Suggested- Ch 29 of SG:
T/F 2,6,7,10
Q&A 1
Probs 3,4,5,6,7,8,10

[27] Magnetic field and forces

Assigned: Turn in a sketch and paragraph that explains the simple motor shown in class (Wed). Your sketch should show the pertinent $\myv B$ field, the current flow, and the forces that arise.

Suggested- Ch 28 of SG:
T/F 1,3,4,5,8,10
Q&A 1
Prob 1,2,3,4,8

[25] Current, Resistance, EMF

Assigned: Turn in Probs 3 and 5 below (from the study guide)

Suggested- Ch 26 of SG:
T/F ---
Q&A 12
Probs 3, 5, 6, 7, 8

[24] Capacitance / Dielectrics

Assigned: Problem 24.70 in Young and Freedman: " The inner cylinder of a long, cylindrical capacitor..." Just like we usually neglect the 'fringing fields' at the edge of a flat plate capacitor, in this problem you should assume that the field has total cylindrical symmetry, so that you can use Gauss'es law to find the Electric field between the inner and outer walls (you should get the same field as for the 'infinite line charge').

Suggested: Chapter 25 of SG:
True/False: 1-4
Questions: 2,3
Problems: 1,3

[23] Electric Potential

Assigned: Discussion Question Q23.12 in Young and Freedman: "A uniform electric field is directed due east....".

Suggested: Chapter 24 of SG:
True/False: 1-8,11,12
Questions: 1-4
Problems: 1,2,4,9

[22] Gauss's Law / vector integration

Assigned: Problem 21.99 in our Young and Freedman textbook: "Two 1.20m nonconducting wires meet....". If the rods were conducting, the charge would concentrate at the two ends of the rod. But on non-conducting rods, we can put a uniform charge charge distribution and the charge will "stick".

Suggested: Chapter 23 of SG:
True/False: 1-4,6,8,10-15
Questions: 1,2,4
Problems: 1,9,11,12

[21] Integration / Electric Field I

Assigned: Show the steps of integration to find the moment of inertia $I$ of a thin, flat disk, rotating about an axis piercing the picture shown at its center. The disk has inner radius $a$, outer radius $b$, and mass $M$. The answer is $I=\frac{1}{2}M(b^2+a^2)$.

Suggested: (quiz / test preparation) Chapter 22:
True/False: 4,6,7,9,10
Questions: 7,8
Problems: 1,5,9