An object falls freely from a height of 25m onto the roof of a building 5m high Calculate the velocity with which the object stricks the roof
calculate the maximum height of a ball of mass 1.4kg will attain if projected vertically upward with an initial velocity of 17m/s

The man of mass m1 and the woman of mass m2 are standing on opposite ends of the platform of mass m0 which moves with negligible friction and is initially at rest with s = 0. the man and woman begin to approach each other. derive an expression for the displacement s of the platform when the two meet in terms of the displacement x1 of the man relative to the platform.