Practice problems

I have just put up a set of practice problems on WebAssign ... it will not be graded, and is optional (in fact, the solutions/answers are immediately available). It is just meant as a study aid.

If you can figure out how to solve most of those problems (say, 75% of them), you will rock the exam.

There will be 10 homework bonus points to the first person to tell me in a comment to this post what is the maximum wavelength of light required to most efficiently break up a diatomic oxygen molecule. If you are the first one within 10% of the optimal wavelength for breaking up an O2 molecule, you win.

Imminent exam

Here's the deal on exam II, which is Tuesday 6 November. Email me if you have questions ...

The exam is problem-based (no multiple choice). You will be given 12 problems, and you can choose any 8 of them to solve. All are equally weighted, simply pick the 8 you feel the best about, and solve those. No, you can't solve 10 and have me pick the 8 to grade ...

Heavy partial credit will be given -- I want to see the right idea, and the right method more than the right number.

You are allowed 2 sides of an 8.5x11 inch sheet of paper with formulas, etc, as last time.

Below is a list of the topics covered, referenced according to both the notes and the book:

Magnetism: 3 questions
Book chapter 20 (notes chapter 7)
excludes torque on current loops and permanent magnets (book 19.5, 19.10, notes 7.3.4, 7.4.1-3)
excludes derivation of B from E via relativity (notes only)
Hint: know and love the mass spectrometer.

Induction: 3 questions
Book chapter 21 (notes chapter 8)
excludes generators (book 20.5, 20.8, notes 8.6)
Hint: voltages induced by the motion of a conductor. RL circuits.

ac Circuits / EM waves: 2 questions
Book chapter 22 (notes chapter 9)
just follow the notes ... filters in particular.
excludes calculations of reactance
includes the EM spectrum, incident power absorbed due to radiation
Hint: filters, power absorbed due to radiation

Reflection/Refraction: 2 questions
Book chapter 22 (notes chapter 10)
excludes Huygens' principle (22.6 in the book, not in notes)
Hint: make sure you know homework 7 and the last quiz.

Mirrors: 2 questions
Book chapter 23 (notes chapter 11, addendum to notes found here)
Follow the latest homework questions.
Hint: make sure you know homework 7.

Suggestions
Study exam II in the course notes packet, and the homework questions relevant to these chapters.

Homework 7 hints

Some hints on numbers 3-5.

Text

Explanatory figure

Additional Explanatory figure

Problems like numbers 3 and 5 would make excellent exam questions.

Problem number 4, speaking from experience, does not.

Next Week

Your second exam is next Tuesday, 6 November. Details will be posted tomorrow, but it is notable that the exam will not be multiple choice. I will try not to make it too pathological. This is the bad news.

Here is the good news: class is canceled on Thursday, 8 November. I am out of town on Thursday next week, and knowing this in advance, I managed to build in a 1-day buffer into the schedule. I did not announce this earlier because I wasn't sure we wouldn't fall behind and need that day to catch up. We have stayed on schedule, as it turns out, so you will reap the reward ... meanwhile, I'll be at a conference in Tampa (so it is not a day off, really).

Take a day off yourselves, or better yet, work on your reports (which are due after the thanskgiving break). That deadline will come up before you know it, don't put it off.

Lab procedure 1 Nov 2007

Here you go.

Today we will measure Planck's constant using a bunch of LEDs, your lab boxes, and a few colored pieces of paper. Weird quantum physics right on your desk.

Intriguing, no?

Lab for 30 Oct 2007

Tomorrow we'll do a lab on lenses, which will signal the beginning of the end of our foray into optics. After this, we are on to quantum/atomic/nuclear physics for the rest of the semester.