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Re: the wall recoils



At 02:27 PM 10/29/99 -0500, Richard Tarara wrote:

... process of converting chemical potential energy (foodstuffs)
to bulk KE, my movement.

That's a correct description of the process and the energy balance.

The only question is, can the wall exert a force on me without moving (a
tiny bit)?

1) The wall does recoil a tiny bit.

2) This motion is important for conservation of momentum. P is significant.

3) In the frame where the earth+wall subsystem is initially at rest, the
recoil makes a negligible contribution to the energy balance. P squared
over 2 M is insignificant.

______________________________________________________________
copyright (C) 1999 John S. Denker jsd@monmouth.com