A boy throws directly downward in ideally elastic ball from theheight 4.80m. The ball is being bounced from the floorreaching certain (unknown) height h. Ignore the air resistance.
a. If the initial speed of the ball is 4.4m/s, what is the speed when it hits the floor?
b. What initial speed should the ball have in order to bounceto the level of the 6.40m above the ground?