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Physics

Kinetic Energy Transfer

Quick fact

In a perfectly elastic collision between two identical objects, the first object stops completely and the second moves away with the first's original speed – the energy transfers entirely.

Why this is interesting

When you throw a rubber ball at a wall, it bounces back almost as fast as it left your hand. But when you drop a lump of clay, it splats and stops. What determines whether energy bounces or gets absorbed?