A body of mass M is dropped from a height h on a sand floor. If the body penetrates x ~cm into the sand, then the average resistance offered by the sand to the body is

Step-by-step solution

Given, mass of body =M Height above the sand floor =h Distance penetrated into sand =x Let v be the velocity with which body strikes the surface. Then, by equation of motion, we get v^2=u^2+2 g h v^2=2 g h ...(i) [ Initial velocity at highest point, u=0] With this velocity v , when body passes through the sand floor it comes to rest after travelling a distance x . Let F be the resisting force acting on body. Then, net downward force will be F_ net =M g-F By work-energy theorem, work done by all forces is equal to c