PH253: HW10 solutions

I have HW10 solutions ready. Given the end-of-semester craziness, I know quite a few of you will turn HW10 in late and take the hit on points. That's fine by me, it is your choice.

Because of that constraint, I had planned to not post the HW10 solutions publicly, but give them out by email to anyone who had already turned in HW10. The idea was that you wouldn't get to see the solutions until I saw your completed HW set.

Of course, that idea was hopelessly naive, and probably just punishes the people who need the most help. 

So, here are the HW10 solutions. I will still accept HW10 up through the final exam, minus the usual late penalty. Remember that I drop the lowest homework.

PH253: HW10 #2

Here are a couple of hints.


Hint the first.
Hint the second.

PH253: more grades on Moodle

Just uploaded HW8 grades, which leaves only HW9 outstanding at the moment. I'll try to have that by the end of the week.

PH253: last homework set

Here you go. Last HW set, due on the last day of class. For those of you attending the last few classes, we will go over the tougher problems.

Keep in mind I drop one homework set, so if you've done them all so far ...

PH253: HW8 & 9 solutions

Partial HW8 solutions (numbers 1-4 only have answers) and full HW9 solutions (rather detailed) are out now.

PH253: HW9

UPDATE: small change to 5c: you can assume the masses and springs are equivalent.

HW9 is out, due next Friday 12 Nov. There are only 5 questions, but you will not like them. ;-)

There will be plenty of hints in the coming week. You will need to recall a bit of mechanics.

HW7 solutions / HW8 due date

HW7 solutions are out. This time, we heavily abuse Wolfram Alpha to avoid a great deal of tedium.

HW8 is due tomorrow, Nov 2. I did not note the time that it was due, but it is the usual 11:59pm ... so you have about 25 hours to go yet.

Good thing, since apparently many of you are affected by a power outage at the moment ...

PH253: HW8 #2

Check it. Good idea to google the phrases I put in italics.

PH253: HW8 is out

Here you go, due Nov 2. I'll be back in town on Oct. 31 and reading email for last-minute questions, and around on Mon Nov 1 all day.

PH253: help on HW

I uploaded some new files here that will be of great utility.

UPDATE: on problem 3b, those should be x's not r's

Also, some useful bits from hyperphysics:

Hydrogen energies & levels:

http://hyperphysics.phy-astr.gsu.edu/hbase/hyde.html#c2

Spectrum:

http://hyperphysics.phy-astr.gsu.edu/hbase/hyde.html#c4

Quantum physics topics:

http://hyperphysics.phy-astr.gsu.edu/hbase/quacon.html#quacon

Schrodinger & Hydrogen concepts, Wave functions & plots:

http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/schrcn.html#c1

http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hydcn.html#c1
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hydwf.html#c1
http://hyperphysics.phy-astr.gsu.edu/hbase/hydwf.html#c1

PH253: HW6 solutions

Here.

PH253: HW7 is out.

Here you are. Due friday.

PH253: Physics help desk

Good news everyone, I've negotiated with the PH10x TAs, and they have agreed that it is OK if you come by the physics help desk for PH253 homework questions.* You can find the help desk hours here. The following TAs explicitly agreed to help with PH253 questions:

Lei Lu, Zachary Burell, Arindam Das, Jason Carson, Chockalingam Sivakumar, Sahar Keshavarz, Christopher Sterpka, Andrea Chaney

I didn't hear back from a few of the TAs when I asked if it was OK for you to come by, but the list above covers most of the available help desk hours. (I said that a lack of response would be construed as a 'yes' on their part though.) I agreed to send them the HW solutions in advance each week so they can better help you.

*Previously, the help desk was only for 100-level physics, but I asked if they would expand their repertoire.

PH253: Unsavory HW6 typo

Indeed, you are right: in problem 1 the width of the well is 2a, not a as I listed originally. The well extends from x=-a to x=a, and has V=0 over that interval. For |x|>a, the potential is infinite. That is why the normalization constant is 1/sqrt(a), not sqrt(2/a).

I've corrected that on the problem set, available at the same place.

Physics tutoring

Two options:

1) I am going to negotiate with the grad students running the physics help desk to let you go to their hours for help. They are only expected to help out with 100-level physics at the moment, but I think they'd be happy to help. Presume you can go to their office hours listed in the link above unless I tell you otherwise ...

2) The physics student society runs study sessions every Sunday evening at 6pm in 109 Gallalee. It is not organized per se, but a group of physics students that get together to work on homework collectively. A lot of them are upper-level students who have already been through PH253, so they can help. I've talked to them, and they are happy to work with anyone who shows up. The main entrance is locked on Sunday, but usually they will have someone manning the quad-side door periodically to let people in. This might be the even better option, sometimes getting some help from someone who was in your position not so long ago is the best.

PH253: HW6 is out

Due next Wednesday ...

Also, a nice applet for visualizing wave functions.

PH253: online grades

I now finally have the system set up so you can log in and see your grades (HW1-3 and Exam 1 right now). Since I am still young enough to be idealistic, I'm using an open source system called Moodle. Apparently you still have to pay if you want a sensible name. Instructions below the jump ...

PH253: HW5, misc

Here is the exam you took yesterday. Your HW5 is to solve the two problems you didn't choose on the exam, due Monday before midnight. My suspicion is that a few of you get together in a group, you've probably solved them all amongst you ...

Also, I'll have your exams back on Tuesday at the start of class.

A recent tour-de-force experiment by NIST managed to demonstrate gravitational time dilation on ordinary length scales. Neat stuff. (We didn't really cover gravitational time dilation, part of general relativity, but there is a small bit on it in your textbook.)

PH253: HW4 solutions

Here you are.

PH253: HW4 hints

I'll be updating these through the evening as I finish them up. The link will be persistent. I'll post here when they are complete.

UPDATE: barring any typos I find later, the hints are about as complete as they are going to get.