2.5 An object A of mass 4 kg slides from rest down a frictionless slope and collides with a stationary object B of mass 2 kg on a horizontal surface. After the collision A continues at 1A mix to the left, while B moves off to the left at 2,6? nu's. (11]) u: diecar A. Calculate the velocity of ball A just before the collision. B. Determine whether the collision was elastic or not. C. At what height h above the horizontal was hall A released? D. If the objects were in contact for 0,02 5 during the collision, determine the force which A exerted on B