Starting with an initial speed of 6.95 m/s at a height of 0.150 m, a 2.84-kg ball swings downward and strikes a 4.97-kg ball that is at rest, as the drawing shows. (a) Using the principle of conservation of mechanical energy, find the speed of the 2.84-kg ball just before impact. (b) Assuming that the collision is elastic, find the velocity (magnitude and direction) of the 2.84-kg ball just after the collision. (c) Assuming that the collision is elastic, find the velocity (magnitude and direction) of the 4.97-kg ball just after the collision. (d) How high does the 2.84-kg ball swing after the collision, ignoring air resistance