A steel ball of mass 0.750 kg is fastened to a cord that is 47.0 cm long and fixed at the far end. The ball is then released when the cord is horizontal, At the bottom of its path, the ball strikes a 4.90 kg steel block initially at rest on a frictionless surface. The collision is elastic. Find (a) the speed of the ball and (b) the speed of the block, both just after the collision.