On Tue, 03 Apr 2007 20:03:52 -0500, John Fields
Gave us:


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

In a word, "heat"


Now... throw the steel ball onto the concrete floor and it fails to
bounce, yet the golf ball comes back to well over 90% of it's original
drop height. If thrown, it rebounds even more.

Place a steel ball on the concrete floor, and the steel ball still
refuses to bounce "right", and a golf ball against a golf ball DOES
bounce.

It has to do with how the shock wave propagates through them.

In my hand, the golf ball couples the wave directly to my hand, and
the dropped/thrown ball refuses to bounce. The steel ball, being so
much more massive, has time (key element) to hold its position long
enough to push back on the dropping steel ball much harder, and there
is enough to actually pop it back up.

Interesting set of tricks to observe there.