A 2-kg sphere A strikes the frictionless inclined surface of a 6-kg wedge B at a 90° angle with a velocity of magnitude 4 m/s. The wedge can roll freely on the ground and is initially at rest. Knowing that the coefficient of restitution between the wedge and the sphere is 0.50 and that the inclined surface of the wedge forms an angle ? =40° with the horizontal, determine
(a) The velocities of the sphere and of the wedge immediately after impact,
(b) The energy lost due to the impact.