In the above problem, the contact force between the man and the crate is

A man of mass M jumps from rest, straight up, from a flat concrete surface. Centre of mass of the man rises a distance h at the highest point of the motion. Find the work done by the normal contact force (between the man’s feet and the concrete floor) on the man.

In the above problem, the force exerted by the seat on the pilot at lowest point is ,

In the above problem, what force should the man exert on the rope to get his correct weight on the machine?

In the above problem, direction of friction force is