I thought that we were discussing the case of M/m >> 1.
ie a momentum transfer very close to 2mv.
[ Your expression is MV = 2mv / ( 1 + m/M ) ]
----- Original Message -----
From: Bob Sciamanda<mailto:trebor@winbeam.com>
To: Forum for Physics Educators<mailto:phys-l@carnot.physics.buffalo.edu>
Sent: Thursday, November 16, 2006 9:56 AM
Subject: Re: [Phys-l] momentum and energy
Al Bachmanwrote:
" > bc forgot that it is the momentum transfer that is constant, not V .
."
Not so.
The momentum transferred from m (initial velocity v) to M (initially at
rest) is:
MV = (2mMv) / (m+M) , which is NOT constant as M/m is varied.
What ARE held constant are the total system momentum and KE.