Question

A 10 kg ball is dropped from a height of 10m .Find (a)the initial potential energy 0f the ball (b)the kinetic energy just before it reaches the ground and (c)the speed just before it reaches the ground.

Answer 1

1) The initial potential energy,U= mg* h

=10❌9.8❌10

=980J.

2) Kinetic energy just before reaching the ground = initial potential energy of the ball =980 J.

3) Speed of ball just before hitting the ground = distance/time ,

V=10metre in the second.