Posted on 11/15/2014 6:04:26 PM PST by TurboZamboni
I had a physics prof that told a longer version of this story. He was famous for going on long treks with a mule to carry his stuff. He came across a shack up in the hills. Most of the glass was broken. Old mattresses and garbage laying about. Everything covered in dust.
“And there - in the middle of nowhere, in this hippy shack, someone had written in the dust on the kitchen’s Formica counter: “Entropy Sucks”.
The question as asked by the physics prof is a double trick question. We are supposed to say there is a force, then he says no because there is no change in momentum, however he is indeed applying a force to the wall, even though there appears to be no movement (change of momentum). The wall deflects ever so slightly like a spring with a very large k and the prof’s fleshy hand distorts under compression. The force would be easier to measure if you placed a bathroom scale against the wall. The magnitude of this (balanced) force could also be measured with strain guages that measure the deformation of the material(s) at the point of contact. The moral is the mechanics of an idealized point mass is very different from macroscopic systems where ‘internal’ forces are very real as any engineer can tell you.
That's the moral of an idealized lesson.
The moral of a macroscopic scholastic system, on the other hand, is never trust a physics teacher - they're tricky suckers.
In the video, Cox says the facility is near Cleveland. Wright/Pat is just outside Dayton. That puts them at opposite ends of the state.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.