At 11:51 AM 1/25/03 -0600, Dan Minette wrote:
----- Original Message ----- From: "Robert Seeberger" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, January 25, 2003 11:23 AM Subject: G-Whiz: Roller Coasters Get Astronaut Rating> > "What we do know, and what has been substantiated by science" Gibson added, > "is that riding a roller coaster imposes less g-forces on the body than > flopping down in a chair, sneezing or skipping rope. Ridding a roller > coaster is far safer than many of our other ordinary daily activities." An interesting related trivia question. Say you drop something solid and moderately hard, like a solid piece of glass or a crystal, on a hard surface, like a tile floor. What are the g forces involved when the glass/crystal hits the floor?
Depends on how quickly the falling object comes to a halt.
Assuming it was dropped from a height h and started at rest, at impact it will be moving downward with a velocity of sqrt(2gh), so the acceleration it experiences will be a = sqrt(2gh)/<delta-t>, where <delta-t> represents the time it takes the object to come to a halt. That would depend on things like the elasticity and tensile strength of the object and the floor, but I don't know of any equation to compute <delta-t>. Probably the best method would be to use high-speed photography to measure the time the impact takes . . .
Alternatively, one could drop the object on top of a platform scale, read the force of the impact off the scale readout (better read fast! ;-) ), then use the known mass of the object to compute the acceleration from F=ma . . .
A third way that comes to mind would be to roll the object down an inclined plane and have it hit a piece of tile like that on the floor at the bottom which is wired to an accelerometer. In this case, the object falls as if it were in a lesser gravitational field of strength g�sin<theta>. (This is what Galileo really did to confirm that bodies of different masses fall at the same rate: roll them down inclined planes to simulate them falling in a lesser gravitational field, and show that they landed at the bottom at the same time.)
HTH.
-- Ronn! :)
Ronn Blankenship
Instructor of Astronomy/Planetary Science
University of Montevallo
Montevallo, AL
Disclaimer: Unless specifically stated otherwise, any opinions contained herein are the personal opinions of the author and do not represent the official position of the University of Montevallo.
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