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COLLISION 2



Thanks to all who responded to my collision question.

Let me try to take it a little further if I may.

The difference between two cars that couple together upon colliding and
two that don't can be quite a simple mechanism that simply latches the
two together. For example, a loop on the one car is caught by dropping
a "pin" through it on the other car at just the right moment.

Given that an elastic collision never happens, I am surprised by the
apparently large difference in surviving kinetic energy between the two
cars hitting each other and the two cars hitting each other with this
"pin" dropped to catch the loop making it inelastic.

Is the difference in the losses of kinetic energy manifested primarily
as heat (deformation) or sound? It does not appear to me that these two
collision would sound very different from each other nor that
significantly more deformation would take place.

I have tried thinking of the deformation as a giant spring between the
two cars. In the elastic case the energy stored in the spring is
recovered as kinetic energy. In the case of the inelastic collision, the
spring finds itself permanently caught in a compressed condition as they
couple and cannot come apart. Is this a reasonable model to present to
beginning students?

I am expressing here what my students always ask when they first study
simple collisions and are looking and momentum and energy.

Thanks again for the insights.
--
David Abineri dabineri@choice.net