Photons

A nice post on how we know they exist. A great blog if you want to learn a bit more about physics.

Availability tomorrow

I'll be around Gallalee from about 11:00 tomorrow, and available up until the afternoon final (modulo ~30min to make copies and so forth).

The exam has been made, and I worked out all the problems to make sure they were reasonable. After doing so, I tweaked a few of them to make them more straightforward ...

Remember, if you have questions about a particular problem during the exam, you should ask. Sometimes the main difficulty is just figuring out what is being asked, and that I can usually help you with.

Notation

So we've discussed the fact that physics notation has quite a bit of historical baggage, and lacks precision at times (same symbol, different quantity ...).

Counterpoint.

Grades updated

UPDATE - lab grades were uploaded incorrectly. Should be fixed shortly.

HW6 grades are up, which means HW7 is the only one outstanding. One HW is dropped, Moodle takes this into account.
Quiz 8 grades are not up yet, but the rest are. One quiz is dropped, and Moodle takes this into account.

Lab grades are up now. Two labs are dropped, and this is accounted for in the Moodle average. Here are the labs I have grades for right now:

• Lab 1 = paper
• Lab 2 = errors (I don't have these grades for some of you from the TAs yet)
• Lab 3 = electric field applets
• Lab 4 = capacitors
• Lab 5 = equipotential lines
• Lab 6 = simple circuits / bulbs
• Lab 7 = resistors
• Lab 8 = RC circuits

Remember, Labs, HW, and Quizzes are 15% each of you total grade, and Exams 1 and 2 are worth 15% of your grade each. Moodle's course total should take this into account properly.

Other than a couple of labs, HW7, and Quiz 8, please check to make sure that your grades seem to be correct. It doesn't happen often, but I do make mistakes. Sometimes it is a typo, sometimes I put a HW set in the wrong pile of papers and it doesn't get graded with the rest. If you're missing a grade you are sure you should have, or the number doesn't seem right, don't hesitate to ask me about it. That's the whole reason for online grades, greater transparency, so you can see what's going on with no surprises. (Of course, that being said, it is hard to keep up with the pace during the summer, so the feedback is not exactly instantaneous.)

Practice Problems

For more practice problems, you might want to start with the following:

HW 12 from Spring 2008 (solution available)

Final from Spring 2008. Though there are no multiple choice questions on your exam, these are worth studying as 'quick drills' to make sure you have the concepts down. (MC answers posted, problem answers are not)


Final from Fall 2007. Answers available for all questions. Again, the MC questions are good for a quick test of what you might want to look at in more detail, or work some longer problems.

Last homework

Here you go. It is due at the start of the final exam.

This homework is just a small review of sorts, with a little stronger emphasis on recent things. They are good practice questions for the final, one or two might even show up in nearly the same form on the final.

(Of course, this small homework set does not cover all the material. More practice problems will be posted tonight that cover most of the remaining material.)

Quiz 7 solution

Quiz 7 now has a solution posted. I'll be updating some of the homework solutions tonight.

Extra credit

Here is your chance for more points. A short paper will replace your lowest non-dropped quiz, HW, or lab. If you missed more than the allotted number of labs/HW/quizzes, for instances, this is kind of a big deal. You can replace a zero grade, and that can help a lot.

If you already have an "A" going in to the final, i.e., >=90% overall grade, I'm not going to read your extra credit submission. Extra credit, in my opinion, is meant to help people that could use a little boost, and may be on the borderline between grades. It is not an insurance policy for keeping your A going in to the final. If you already have an "A" you are better off studying for the final, rather than writing me a paper.

I suppose that isn't really fair, in some sense. In another more real sense, I shouldn't offer any extra credit at all, so take it when you can get it :-) It costs me a good amount of time to offer this, so I only want to entertain it for those who really need it.

More grades

HW5 grades are now posted on moodle. If you don't have a score for HW5, but are sure you've turned it in, feel free to remind me. I didn't quite get through that stack of homework this evening.

HW6 & 7 grades will follow tomorrow evening, along with some of your lab scores. Most of the lab scores you know already, but I will post what I have from the TAs tomorrow.

Final exam time

Thursday, 2pm: FINAL EXAM for 1-2:45 class
Friday, 8am: FINAL EXAM for 10-11:45 class

No, I don't like the 8am exam either, and I always seem to get that slot. Nope, I don't know why the exam time isn't the same as the class time ... that would make sense ... I've been wondering that for 5 years now. Not much we can do about it, but at least it is just one day.

If for some reason you have a conflict with the final exam time (a conflict which is more serious than 'it is way early and I don't want to get up,' for instance another final exam), we should talk soon to arrange something else.

Final exam

The following topics will be fair game for the final (text sections in parentheses). If I don't list it, it isn't covered. The listed sections in the textbook relate directly to sections in the notes, if you look at the topic headings for each section.

Relativity (26.1-6)
Electrical forces and fields (15.1-6,9)
Electrical energy (16.1-4,6-10)
Current & resistance (17.1-4,6)
dc circuits (18.1-5)
magnetism (19.1-9, excl. Ampere's law)
induction (20.1-6)
ac circuits / EM waves (21.1-3, 7, 10-12 + filters)
Reflection & refraction (22.1-5, 7)
Mirrors / lenses (23.1-6)
Quantum physics (27.1-2, 5-8)
Atomic physics (28.1-4)

Parts of chapters 27-28 we have not covered yet, and that is the subject of the lectures on Tues and Wed.

The exam will be broken up into (probably) three sections, and in each section you will have to solve something like 3/4 or 3/5 problems. The sections will be logical groupings of material, for example:

Section 1: electric forces, field, energy
Section 2: current, resistance, dc circuits
Section 3: magnetism, induction, ac circuits
Section 4: optics
Section 5: quantum, atomic physics

I'm not saying this is exactly how it will be, but more or less.

Thoughts on the final

I posted this last year, and it still stands. Here are some of my random thoughts on the final. It goes to 11.

(1) Relax. There is no reason to be more freaked out about this exam than any other, percentages and so forth notwithstanding. You should be less scared: broadening the scope of the material necessarily means that the difficulty level for any given problem goes down.

(2) There is only one way to study for this thing: read and solve problems. You will be given all of the required formulas, memorizing them will not help, nor will memorizing tricks or shortcuts. All problems will involve the systematic application of simple principles and simple relationships, there are no tricks. Rote memorization / cramming is not useful, but solving practice problems is.

(3) Cut your losses on the one chapter you really don't think you can master in the time remaining. You'll have a choice in problems, so you can avoid certain topics if you know the rest very well.

(4) Look at the previous final exams (spring/fall semesters mainly). They mostly don't have posted solutions, but I can tell you the answers at least.

(5) Few problems I have asked you before will appear on the final. Most likely no problems directly from the notes will appear on the final. However, about half of the problems will seem eerily familiar.

(6) Relax. You will need to have your wits about you, the problems on the final will involve logically solving problems step-by-step using simple rules. They will not involve remembering an arcane phrase or formula buried in the text, nor will they have many convoluted twists and turns. Most of them involve only 1 or 2 steps.

(7) Run the numbers on your grade. The final is worth 25% of the total grade ... it can only change your overall grade by so much. Not as much as you think. I will scale the average on the final if necessary, such that it is at least 75% for the class. It is unlikely to be necessary.

(8) I like crystals and mass spectrometers and circuits. Capacitors have been done to death though.

(9) Study the homework solutions I have online.

(10) Seriously, relax. Get some rest the night before, you'll be better off well-rested.

(11) Answers/solutions to your outstanding homework/quizzes will posted soon, and will be good to study from.

Grades / this week

I just posted Quiz 6 & 7 grades on Moodle, the homework grades will be updated later tonight.

Tomorrow, your quiz is on photons - energy per photon (E=hf), intensity of a beam of photons, etc.

Wednesday, several things will happen.
1) During the lab sessions, there will be a chance for review.
2) There is no real lab, you'll do the post-assessment test (worth some bonus points) and evaluations.
3) I will discuss a few things related to the logistics of the final exam.

Later tonight, I will be posting details about the final exam, and how to review for it. Tonight and tomorrow I'll be posting some of the HW and quiz solutions so you can use them for studying as well.

Finally, I will there will be a possibility for extra credit I'll post about tonight or in the morning.*

*If you have >90% in the class, I really don't want to see an extra credit assignment from you. I'll go over formal ground rules for the extra credit tomorrow, but it is not meant to be an insurance policy for those of you already getting a solid "A." The idea is to have a way to boost your grade if you're on the border line, etc.

Exam II grades

Your exam II grades are up on Moodle ... you'll get them back tomorrow. The average was 85/81 for the am/pm sections, so most of you should be happy. I was, anyway.

Tuesday, I should have the homework and quiz grades mostly up to date, and I have more lab grades from the TAs as well. At the very least, before the final you will know what your grade is going in.

This is a problem in teaching physics

Precision in language is important, but it is a slippery slope.

Monday's lecture

Monday, we'll start on Quantum Physics, and you'll do an associated lab on atomic spectra. I'll post that procedure tomorrow when the server is powered up again ... the power is off across most of campus!

UPDATE: servers are back up. Here is tomorrow's lab.

No quiz tomorrow. Be ready for one on Tuesday, and a review homework due Wednesday. Really, it will help with the studying ...