Question

When a diver jumps from the spring bolt he curls his body arms and legs. Why?

Answer 1

Conservation of angular momentum. There is this relationship that must be conserved as the diver does somersaults:

Angular Momentum = L * w

Suppose L is the length of the body, and w is how fast they are spinning. Since Angular Moment is conserved (it’s a constant), then if L goes down, w goes up. If w goes down, then L goes up.

So if they curl into a ball, L goes down, and they will spin faster.