Why do countermovement jumps produce more flight time than s

Why do countermovement jumps produce more flight time than static jumps?

Solution

countermovement jumps produce more flight time because Such a movement makes use of the ‘stretch-shorten cycle’, where the muscles are ‘pre-stretched’ before shortening in the desired direction.

and higher vertical push-off range that is wasted in a squat jump while the muscles build up to maximum force. This kind of jump thus performs more work early in the upward phase of the jump, and so this kind of jumping ( countermovement jumps ) has a higher takeoff velocity and a greater jump height.