Free Fallin'!

Welcome to fall!! Today is the autumnal equinox (technically at 4:18 pm CDT), when the sun passes directly above the equator. Today's daylight hours are the same length for everyone at the same latitude - north or south of the equator.

We have been discussing free-fall and forces in PHYS 201, and Dr. van Howe posed a good puzzle that I will pass on to you. Suppose you hold a spring and let it hang vertically. It will be stretched out due to the weight that is hanging from it (or even just due its own weight). What will happen to it, if you let go - let it fall freely (by free-fall, I mean that gravity is the only force on it - assume no air resistance)? Will the top accelerate up or down? Will the bottom accelerate up or down? What will happen to the amount of stretch - same? more? less? Hmmm.... Free Fallin'! We can call this a blog contest, even though I currently have no Whitey's certificates to award (I'll get right on that!)

Also, a local TV station seems to have fallen for one of my students (ok - I know that's a stretch to make this fit with the title of the post - but how much of a stretch would it be if it were in free-fall?) Anyway, Blaine Westmeyer is a student in modern physics - he apparently is such a good student/athlete that channel 6 news wanted to do a story on him. So... they came to my classroom with their TV camera. Yeah - it made me nervous, even though I was just an extra in the story! If you want to see the video, select 5:00 news Sep. 20, 2009. The segment on Blaine is more than half-way through the newscast.