Question

A metal ball of mass 2kg is allowed to fall freely from rest from a height of 5m above the ground. Taking g = 10ms-1, calculate:
(a) the potential energy possessed by the ball when it is initially at rest.
(b) the kinetic energy of the ball just before it hits the ground?
(c) What happens to the mechanical energy after the ball hits the ground and comes to rest?

April 24, 2024

Answer

Mass (m) = 2 kg

Height (h) = 5m

(a) (i) the potential energy possessed by the ball when it is initially at rest = mgh = 2 × 10 × 5 = 100J

(ii) As we know that,

The kinetic energy of the ball just before hitting the ground = initial potential energy = mgh = 2 × 10 × 5 = 100J

(b) The mechanical energy of the ball gets converted into heat and sound energy after the ball hits the ground and comes to rest.

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