700-g sphere A moving with a velocity v0 parallel to the ground strikes the inclined face of a 2.1-kg wedge B which can roll freely on the ground and is initially at rest. After impact the sphere is observed from the ground to be moving straight up. Knowing that the coefficient of restitution between the sphere and the wedge is e 5 0.6, determine (a) the angle u that the inclined face of the wedge makes with the horizontal, (b) the energy lost due to the impact.