This is probably really easy, but I can't figure out what to do. A man of mass 80kg (W= 176 lb) jumps down to a patio from a window ledge .50m (1.6ft) from ground. He doesn't bend his knees on landing so his motion is arrested in a distance 2.0cm (.79in) What is the acceleration of the man from the time his feet first touch the patio to the time he is brought fully to rest? With what force does this jump jar his bone structure? If someone could just lead me in the right direction, that would be helpful.