Physics
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:
- the potential energy possessed by the ball when it is initially at rest.
- the kinetic energy of the ball just before it hits the ground?
- What happens to the mechanical energy after the ball hits the ground and comes to rest?
Work, Energy & Power
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Answer
Given,
Mass = 2 kg
Height = 5m
(a)
(i) the potential energy possessed by the ball when it is initially at rest = mgh = 2 x 10 x 5 = 100J
(ii) As we know that,
The kinetic energy of the ball just before hitting the ground = initial potential energy = mgh = 2 x 10 x 5 = 100J
(b) 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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