On Tue, 03 Apr 2007 17:42:40 -0700, MassiveProng
wrote:



another question:

Bounce a steel ball off another held in the hand causes the ball to
rebound nearly back to the hand that tossed it.

Doing the same with two golf balls results in nearly no bounce, and
a nearly dead impact.

Wouldn't both cases be "elastic" or "inelastic" collisions?

Why can the golf ball not be made to rebound regardless of how hard
it gets thrown into the other?

Again, you have to do the math.

In an elastic collision, no energy is lost. So, say, a perfectly
springy steel ball is floating free, motionless in space relative to
our frame of reference. An identical ball comes sailing in at some
constant velocity V and smacks the stationary ball dead-center. What
happens to the first ball? To the second?

Repeat for an inelastic collision, two balls made of putty.

Conservation of energy and conservation of momentum answers both
cases.

How about an intermediate case, say two golf balls that are
imperfectly springy? That's also inelastic. What happens?

John