Answer to Question #56283 in Mechanics | Relativity for Oluwasegun

Question

18 a boy throws a ball vertically upward with a speed of 15.0m/s. what is its speed just before the boy catches it again?

11.5 m/s downward

225.0 m/s downward

15.0 m/s downward

250 m/s downward

Answer 1

If we assume that there is no air resistance we can describe the motion of ball as the object under the action of gravity force. According the conservation of energy law the speed of the ball would be the same at the same height. But now the ball move downward.
Answer: 15.0 m/s downward.