HW2 problem 5

On problem 5, I failed to specify the coefficient of friction between block b and the flat surface. Take it to be 0.20.

Also note that the ramp can be treated as frictionless, only worry about friction for the flat surface.

The Snowpocalypse continues

We'll have to play this by ear, but here's the current plan:

• HW due Friday by midnight, presuming UA is open Friday. 
• Friday's class: work homework problems, review for the exam. 
• Exam on Monday, but taking only ~50 minutes. We'll spend the rest of the class period working problems and discussing new material.

Given that it is supposed to be in the high 40's tomorrow at least, I fully expect we'll have class on Friday. I don't think we'll know whether UA will be open tomorrow (Thurs) until ~4pm today.  UA is closed Thursday. Presuming we have class on Friday, we'll spend most of that time working on homework and getting you ready for an exam on Monday.

Snowpocalypse 2014

I'm going to make a wild leap and assume classes will be held tomorrow.

On the outside chance that they are not, the HW due date and exam will shift by one class. Specifically, if there are no classes tomorrow, the HW will be due on Friday and the exam will move to Monday. Again, so long as classes are still on tomorrow, the HW is due Wednesday and the exam will be Friday.

Right. Better get back to shoveling my car out of the snow drifts so I can stock up on bread and milk.

Wednesday's lab

Here you go - just like one of the problems we worked out in class today.

Speaking of Wolfram Alpha

You'd be surprised what it will answer. It knows physics too, not just math ...

Using Wolfram Alpha

It can be a bit tricky to get Wofram Alpha to understand what you want. A couple of key tricks (and I'll give examples) to make it easier:

Field trip opportunity. Seriously.

I would like to point out an opportunity for a 3 week field trip to Yellowstone for under-represented students in the sciences.

More info can be found here:

http://physics.ua.edu/news/Yellowstone_FieldCourse_Brochure.pdf

The deadline to apply is 1 Feb 2014. The application is on the last page of the brochure linked above

Homework 2

Homework 2 is out. You do have one daily problem due Friday, but it (should be) relatively quick. Some of the problems are more involved than last week, so don't put off the rest of the problems ... we will do at least a few of them in class on Mon & Wed next week.

[Hint on the first daily problem: it is easy to write down the equation of motion for either car. The tricky part is making sure that their time coordinates agree. You might call t=0 the moment when the cop starts moving, and say the other car passed it at t=-2 seconds (time can be negative, that's fine). You could also call t=0 the moment the car passes the cop, and write the cop's position in such a way that it is 0 after 2 seconds, and following accelerated motion after that. Either way describes the same situation and the same physics, the math is slightly easier for one of the choices.]

Homework 1 solutions

HW1 solutions are available. Let me know if you notice any errors.

Tomorrow's lab

Here is the background reading and procedure. Please read it before tomorrow's class. You can print it when you arrive, no need to print it at home. Depending on how the time goes, we may finish the prep questions and writeup on Friday.

You might also find this derivation of linear regression interesting, but it is not required reading.

Next HW

Owing to the long weekend, I'm delaying putting out the second HW until Wednesday. Seems more realistic. I should have HW1 solutions out at that time as well. 

Submitting homework

The first homework submission went very well I thought. I've been accepting email homework quite a while now, and this was probably the easiest first homework submission I've had.

That being said, here are a couple of suggestions that will make the process easier for me:

In case you are interested

UA Society of Physics Students First Meeting of the Semester!

When: 6:30 PM Wednesday January 22nd

Where: Gallalee Room 200

What:

• Discuss semester activities 
• Watch The PHD Movie

Help Desk

The class may seem difficult so far. It should, we are starting off with pretty tough pace. I'm not going to promise that it will slow down or get a little easier, but I think it will. In any case, at this point trying to finish up the first homework set you may be wanting a little extra help, and we've got you covered.

All the intro physics TAs pool their office hours together to staff our physics Help Desk. You can find a schedule of available TAs and which room they will be in here. You can pick any time slot that is staffed and just show up to the relevant room, so you have lots of chances to go and ask questions.

(You can also always stick around after class and ask me questions, or come to my office hours too.)

Exam duration / syllabus confusion

The syllabus is not totally clear as to how long the exams are. The in-class exams will all be 50 minutes long, no matter what day they occur on. 

There is some confusion because my original (internal) schedule had all the exams on M or W, presupposing rather long exams. After rethinking it a bit, the exams didn't end up coming at natural logical breaks in the course material, and of course long exams just suck. At that point, I moved the exam dates around, putting most of the exams on Friday instead (so long as there was a natural conceptual break in the material), but forgot to update the syllabus. (One exam remains on a Monday because the preceding and following Fridays would make for awkward exam coverage.)

What the syllabus should say is that all four "hour" exams will designed to take 50 minutes, independent of what day they are on. For the one exam scheduled on Monday, you will still have a 50 minute exam, not a 110 minute exam. We will probably use the remainder of the 110 minute class period to review or do a short lab.

Solutions for quiz 1, 15 Jan daily problem

Quiz 1 and solution.
15 Jan daily problem and solution.

Solution to Monday's daily problems

Here you go. Let me know if you see any mistakes.

Lab 1 / Wed 15 Jan

On Wednesday, we'll do a lab on uncertainty analysis.

You don't need to print this out, just read it before Wednesday's class. You can print what you need in the classroom when you arrive. Please just print one copy per group, you'll be working in groups of 3-4.

Webassign / Textbook

Some of you have been wondering, and I wasn't crystal clear about it - you don't need a WebAssign code with your textbook. Your homework is purely pencil & paper type stuff.

If you already got a WebAssign code with your book, the chances are extremely high that someone in one of the PH105 sections could use it, or you could just try to exchange it.  

Reading for Friday

For Friday, the reading is Halliday, Resnick, and Walker Ch. 2 (motion along a straight line). You should also skim Ch. 1 (physics & measurement) to make sure it all makes sense - most of it should be review I suspect, and most of those topics will come up naturally as the semester progresses.

If you're looking for a little something more, you can check out the Fenyman Lectures on Physics, specifically Volume 1, Ch. 8. Much of the supplemental reading I'll post will be from the Feynman lectures (called 'FLP' on the schedule).

Homework 1

Here is your first homework set. Note that there are multiple due dates - you have two problems due at the start of class 13 Jan, one due at the start of class on 15 Jan, and the rest are due by the end of the day on 17 Jan. Also note that I would like you to use the problem template format when turning in homework.

Course intro slides

Here are the slides I'll use at the start of the first class to go over the course format, etc.

Welcome to PH125 / Spring 2014

This is where you will find all the information you need for PH125 this semester. If you are in to such things, subscribe to the atom feed, it will make things easier. 

Be sure to note the handy links on the left sidebar. In particular, note that all course content from Spring 2009 is available, including old homework and solutions. The Feynman Lectures on Physics are also a great resource in addition to your textbook.

Your syllabus is already online for your perusal; read it carefully!