A student m 66 kg falls freely from rest and strikes the gro

A student (m 66 kg) falls freely from rest and strikes the ground. During the collision with the ground, he comes to rest in a time of 0.04 s. The average force exerted on him by the grounds is + 18000 N. where the upward direction is taken to be the positive direction. From what height did the student fall? Assume tha the only force acting on him during the collision is that due to the ground. H = the t the tolerance is +/7%.

Solution

H = F² * (delta t)² / 2 a_y m²

= (18000² * 0.04²) / ( 2 * 9.8 * 66²)

= 6.07 m