Rocket Contest

Well, I was pleased, and had a good time :-) I thought it went well, and you all did a great job. The visitors were pretty impressed with what you were able to come up with, and in particular the variety of solutions presented.

By the way: no one will come out of this with a bad lab grade, I was impressed all around. Even if you didn't get as many 'hits' as you would have liked, it was clear you all had solid approaches and took the task seriously, and that's worth a lot.

Currently, I'm uploading many photos and some video from today, but I'm not quite finished yet ... I'll post some links here when it is finished. Keep your eyes on the Tuscaloosa news, they may run a story based on the video and pics they took today.

Also: I've decided you can keep the launchers, sensors, and laser pointers - your lab fees more than paid for them, and at this point you put a lot of work into the customizations. I do need the voltmeters back if you still have them though ...

In the mean time: here is (1) a UA news bit, (2) a short video of a successful shot, thanks to Marcy Huey's fine camera work, and (3) a listing of several other videos, including team Red Scare's propaganda.

(All videos are AVI straight from my camera; editing and conversion to mpeg should happen this weekend I hope.)

Kobe Bryant jumping over a car

Remember the video about the decay rate on a head of beer?

Turns out the author is one of our own alumni, and he has a fantastic blog with all sorts of interesting 'real world' physics problem, including a lot of video analysis and simulation.

For instance, here is an analysis of a video showing Kobe Bryant jumping over a car. Real, or not? Physics can help decide ... the same physics we just finished going through.

Check out the rest of the blog if you like seeing some more fun examples of what we've been doing.

Lecture video / office hours today

Based on the poll response so far, I'll begin taking video (and audio) of the lecture portion of class starting tomorrow. I would have started yesterday already, but forgot the mic ...

If you are having trouble with the homework problems for tomorrow, I'll be in my Bevill office and mostly available after 2pm today. Failing that, I should be in my Gallalee office for the hour before class tomorrow.

Finally ... the notes I posted contain a huge hint for problem 9 on the homework. For problem 8, first find the acceleration vector, and then note that

a_t = \vec{a}\cdot\hat{T} = \vec{a}\cdot\frac{\vec{v}}{|\vec{v}|} = \frac{\vec{a}\cdot\vec{v}}{|\vec{v}|}

and

a_n^2 = |\vec{a}|^2 - a_t^2