To a first approximation, is it legitmate to just do Newton's Law of
Universal Gravitation for two points with a change in r of about two meters?
I have often found that just playing with some numbers, especially on a
spreadsheet can help students get a feel for the algebraic expression. I
have done a related exercise measuring the difference in centripetal force
between two points on a proposed space station to argue that space stations
need to be pretty big not to have a steep centripetal force gradient.
Marc "Zeke" Kossover
(who still translates "grad" to graduate student even after many years in
physics.)
-----Original Message-----
From: Jack Uretsky
To: PHYS-L@lists.nau.edu
Sent: 11/27/01 6:29 PM
Subject: Re: Black Holes and tidal forces
1. Yes, of course. So don't use the word "gradient" in polite
company.
2. Say something like: "gravity is pulling a lot harder on your
feet (if you're falling feet first) than it is on your head, so pretty
soon you get like stretched way out of shape."