Final solutions

Or, at least the multiple choice section. Re-read the homework and quiz solutions, and you will find many of the solutions to the problems section.

Exam II solutions

Here you go, for the last-minute cramming.

Homework 12 solutions

Here they are, almost complete. Only the one about the ring of charge is not yet complete, but I assure you that particular problem will not show up on the final exam.

For more last-minute fun, here's a draft of the formula sheets I'll be including on the final. This is not final, has not been proofread, etc., but gives you an idea of what to expect.

Also: relax. If you've been going to class and following the homework/quiz solutions, you have nothing to worry about. Most important will be to keep your cool and use your time wisely on the final - don't get stuck on any one question for too long, and don't panic.

Correlation between homework and pre-final grades

This isn't particularly shocking, but there is a 87% correlation between your homework average grade and your up-to-the-minute overall grade.

There is not a lot of hidden meaning here: if you did your homework, and did it well, you scored well on everything else by and large. We can say with (much) better than 99.95% confidence that your homework score is a good predictor of your total grade. This establishes correlation but not causation, though in this case I would hazard a guess that doing your homework in fact causes you to do well on everything else.

My current theory is that the final exam scores will follow this plot as well, supposing that it is a bit late to catch up on everything at this point. I am hoping, though, that you prove me wrong!

Final exam format

FRIDAY 9 May, 8am-10:30am
329 Gallalee

As we discussed today, the final exam will consist of two parts:

Part I: Multiple choice. Worth 50% of the exam grade, approximately 20 questions. Roughly half will be conceptual, roughly half involving simple calculations. Solve them all.

Part II: Problems. Worth 50% of the exam grade, you will solve a certain number of problems in each of 7 sections, for a total of 11 problems. You must solve the indicated number of problems in each section.

• Electric forces, fields, and energy: solve 2 of 5.
• Current, resistance, and dc circuits: solve 2 of 4.
• Magnetism & induction: solve 2 of 4.
• ac Circuits & EM waves: solve 1 of 3.
• Optics: solve 2 of 4.
• Relativity: solve 1 of 3.
• "Modern" Physics: solve 1 of 3.

You are allowed two full sheets of standard 8.5x11" paper, front and back, with formulas and so forth. I will provide most formulas and all numerical constants (masses, etc.) on the exam. Beyond your formula sheets, you are allowed only writing implements and a calculator.

The final is worth 20% of your total grade.

Post any questions you might have here, so I can easily answer them for everyone.

Special topics lecture next tuesday

On Tuesday 28 April, we have a "special topics" lecture scheduled. If you can suggest anything - related to the ph102 material, at least tangentially - that you might be interested in hearing about, let me know before the end of the weekend.

If there are several topics I think I can work up on short notice, I'll pick the one I think has the most broad appeal. If no one suggests anything, I will talk about what it is I do.

Other possibilities:

• how does MRI/PET/CAT work?
• how does your iPod work? (related to what I do)
  
• more bad movie physics
• how do semiconductor devices (transistors/flash/whatever) work?
• length scales, from nuclei to galaxies
• something you think I did a poor job explaining the first time around :-)

Leave a comment here (or email me) to vote on one of these, or suggest another topic.

And no, it won't be on the final. This one is supposed to be purely curiosity-driven, "for fun."

Lab for Thursday 24 April

Today, we will put the Bohr model of the atom into practice, and measure the atomic emission spectra from Mercury and Hydrogen.