In the vertical jump, an athlete starts from a crouch and jumps upward to reach as high as possible. Even the best athletes spend little more than 1.00 s in the air (their "hang time"). Treat the athlete as a particle and let you be his maximum height above the floor. To explain why be seems to bang in the air, calculate the ratio of the time be is above Ymu/2 to the time it takes him to go from the floor to that height. You may ignore air resistance.