An athlete who is initially at rest in a squatted position jumps vertically upward and then lands going back to the original squatted position (ending at rest with the same center of mass height as at the start). The time period under consideration begins just before the athlete starts the upward motion and ends just after she has landed and comes to rest back in the squatted position. Compare the magnitude and directions of the impulse from the force of the ground on the athlete to the impulse from gravity on the athlete during this time period. Note: there are no other significant forces other than the ground and gravity acting on the athlete during this time period.

An athlete who is initially at rest in a squatted position jumps vertically upward and then lands going back to the original squatted position (ending at rest with the same center of mass height as at the start). The time period under consideration begins just before the athlete starts the upward motion and ends just after she has landed and comes to rest back in the squatted position. Compare the magnitude and directions of the impulse from the force of the ground on the athlete to the impulse from gravity on the athlete during this time period. Note: there are no other significant forces other than the ground and gravity acting on the athlete during this time period.