**Day 1: Monday*** Before* Monday’s Class:

1. Read 16.10. most important is how we get to form beats and standing waves from two waves adding. Note how we get to equation 16.72 from 16.71 by using the third of the four “superposition relationships” at hyper physics. Are you ready to take Part I of the midterm from 2012 (posted on main webpage)?

2. Read 17.5 in your text. Pay particular attention to the diagrams 17.28, 17.29, 7.31, and please follow how to do example 17.5.

3. Please see video on standing waves, beats, and music.

4. Have a look at PS#3 just to see what to expect from the coming week.

__In Class__: talk about music and solve problems.

__After Class:__

**Day 2: Tuesday** *180-262, not in the SUSTAIN room** Before* Tuesday’s Class:

Read 17.6 in your text. PS#1 Solutions Posted on Main Webpage.

__In Class__: BIG EXAM 2 today! __ COLLECT PS#2__, And then, Study beats, and trigonometric superposition relationship at hyper physics.

**Day 3: Wednesday: 180-269**

Vibrating Strings and the speed of the wave!__Before lab:__ This ridiculous video from NPR is exactly what we’re doing today – making an interferometer – a standing light wave. So please see it.

I’ve posted solutions for Tuesdays Big Exam on the main page. I’ve also posted a solution for the Doppler Shifting problem.

I put a practice 122 midterm from another professor on the main webpage. Please notice how *very* similar the material is. Please look at this even if you are in 132 because any of these questions are possible for either 132 or 122.

I’ve posted the procedure for the lab. Do you see how it is (kind of) the same as the ridiculous peeps video?

During Lab:

**Day 4: Thursday Meet in 180-262, not in the SUSTAIN room**

2-D wave interference

__Before Class:__read Chapters 27.3, and 27.4, with particular,

*particular*attention on fig. 27.14 -and fig. 27.19. Please be prepared to reproduce this figure, identify the similar triangles and explain where equation 27.5 comes from in your exams. Think about this triangle when you watch this Veritassium Video

I’ve posted solutions for Tuesdays Big Exam on the main page. I’ve also posted a solution for the Doppler Shifting problem.

I put a practice 122 midterm from another professor on the main webpage. Please notice how *very* similar the material is. Please look at this even if you are in 132 because any of these questions are possible for either 132 or 122.

__In Class__: Exploring sound interference.

__After Class:__ If you are challenged with the explanation of the two slit experiment, please see the reading assignment above, and in particular, look at fig. 27.13 and 27.14