A 60 kg man leaps vertically from a crouching position when his centre of mass is 40 cm above the ground. As his feet leave the floor his centre of mass is 90 cm above the ground and rises to 120 cm at the top of his leap. Calculate up upward froce, assumed constant, that the ground exerts on the man.
[Hint : Human body is a system of particles]

A man whose mass is m kg jumps vertically into air from a sitting position in which his centre of mass is at a height h_(1) from the ground. When his feet are just about to leave the ground his centre of mass is h_(2) from the ground and finally rises to h_(3) when he is at top of the jump . What is the average upwards force exerted by the ground on him ?

A man whose mass is m kg jumps vertically into air from a sitting position in which his centre of mass is at a height h_(1) from the ground. When his feet are just about to leave the ground his centre of mass is h_(2) from the ground and finally rises to h_(3) when he is at top of the jump . What is the average upwards force exerted by the ground on him ?

A man whose mass is m kg jumps vertically into air from the sitting position in which his centre of mass is at a height h_(1) from the ground. When his feet are just about to leave the ground his centre of mass is at height h_(2) from the ground and finally centre of mass rises to h_(3) above the ground when he is at the top of the jump. what is the average upward force exerted by the ground on him?

A man whose mass is m kg jumps vertically into air from the sitting position in which his centre of mass is at a height h_(1) from the ground. When his feet are just about to leave the ground his centre of mass is at height h_(2) from the ground and finally centre of mass rises to h_(3) above the ground when he is at the top of the jump. what is the average upward force exerted by the ground on him?

An unruly demonstrator lifts a stone of mass 200 g from the ground and throws it at his opponent. At the time of projection, the stone is 150 cm above the ground and has a speed of 3.00 m/s. Calculate the work doe by the demonstrator during the process.

Explain why , a runner presses the ground with his feet before he start his run.

Find the pressure exerted by a man weighing 90 kg on the ground.When he is lying flat. The area of his body is contact with the ground is 0.9 m^2 .