PHYS 2170: Weekly Homework Assignment

Due Wednesday, September 2, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 1.5, 1.8, 1.12, 1.14, 1.15, 1.17, 1.20

Solutions available as PDF file here.

Due Wednesday, September 9, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 1.19, 1.22, 1.26, 1.28, 1.29

Solutions available as PDF file here.

Assignment #3:

Due Wednesday, September 16, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 1.43, 1.46, 2.2, 2.6, 2.12, 2.16, 2.18, 2.27

One more problem: Special Relativity shows us that time intervals between events can be different in different inertial reference frames. However, for some events, they are causal (i.e. A causes B). Thus, it would not make sense in any inertial reference frame for B to come in time before A (that would violate causality).

Consider a particle called the pion that decays into a muon. Consider this decay to be event A and that it takes place at spacetime coordinate (x1,t1) in some particular inertial reference frame. Now some time later the muon has moved some distance and it decays into an electron, call that event B that takes place at spacetime coordinate (x2,t2). In this inertial reference frame S, x2 > x1 and t2 > t1 and the velocity of the muon is v=(x2-x1)/(t2-t1). Is there any inertial reference frame that violates causality? Prove it.

Solutions available as PDF file here.

Assignment #4:

Due Wednesday, September 23, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 3.15, 3.28, 3.31, 3.40, 3.45

Solutions available as PDF file here.

Assignment #5:

Due Wednesday, September 30, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 4.6, 4.9, 4.14, 4.18

Additional (and still required) Problems:

5A. You attend the opera and are sitting in the back row (50 meters away from the singer). Your friend is at home 3000 kilometers away listening to a "live" radio broadcast of the opera on the FM station 93.5 KPHYS with their headphones. Assume that the microphone is a few centimeters from the singer and that everywhere the conditions are STP (standard temperature and pressure). Who will hear the voice of the singer first? How much sooner?

5B. Some snakes haave two pits on the front of their face lined with temperature sensors. These sensors can effectively detect infrared radiation by its local heating from radiant heat at wavelengths between 5 and 30 micrometers. How cold would a mouse need to be to escape detection? Hint: We will discuss Wien's Law in Monday's lecture.

Solutions available as PDF file here.

Assignment #6:

Due Wednesday, October 7, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 4.12, 4.15, 4.28, 4.29, 5.2, 5.6

Additional (and still required) Problems:

6A. In the PHeT simulation of the Photoelectric effect, sketch the results obtained using different metals. Explain why the different metals have different results.

Solutions available as PDF file here.

Assignment #7:

Due Wednesday, October 14, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 5.10, 5.13, 5.16, 5.19, 5.24, 6.2, 6.9, 6.17, 6.19, 6.30

Additional (and still required) Problems:

7A. In the PHeT simulation of "Neon Lights and Other Discharge Lamps", for the single atom case and the largest Voltage, write out the various wavelengths of light emitted. Calculate the corresponding energies and try to map out the various energy levels. Do this for the hydrogen case and sodium. Note that you can see the different wavelengths as a histogram if you select the "Spectrometer" box.

Solutions available as PDF file here.

Assignment #8:

Due Wednesday, October 21, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 6.31, 6.33, 6.42, 6.44, 6.47, 7.3, 7.14, 7.17

Solutions available as PDF file here.

Due Wednesday, October 28, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 7.27, 7.30, 7.35

Additional Problem: Fill out the following on-line survey here. It takes about 15 minutes, counts for one homework problem of credit, and your individual answers are anonymous.

Solutions available as PDF file here.

Due Wednesday, November 4, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 7.10, 7.11, 7.12, 7.13, 7.16

Solutions available as PDF file here.

Due Wednesday, November 11, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 7.26, 7.32, 7.39, 7.44, 7.51, 7.53, 7.54

Solutions available as PDF file here.

Due Wednesday, November 18, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems given in this PDF file here.

Solutions available as PDF file here.

Due Wednesday, December 02, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 8.4, 8.9, 8.11, 8.18

Solutions available as PDF file here.

Due Wednesday, December 09, 2009 at 9:50 am.

Handed in at the wooden box outside the Physics Help Room (Duane 2B Level)

Problems from Text: 8.28, 8.30, 8.39, 8.43 (and the online survey -see main web page link)

Solutions available as PDF file here.