A metal ball of mass 2kg is allowed to fall freely from rest from a height of 5m above the ground. - Noon Academy

A metal ball of mass 2kg is allowed to fall freely from rest from a height of 5m above the ground.

Class 10 | ICSE | Physics | Selina | Work Energy

A metal ball of mass 2kg is allowed to fall freely from rest from a height of 5m above the ground.

(a) Taking g = 10m/s², calculate:

(i) the potential energy possessed by the ball when it is initially at rest.

(ii) the kinetic energy of the ball just before it hits the ground?

(b)What happens to the mechanical energy after the ball hits the ground and comes to rest?

Solutions:

(a)

(i) Potential energy of the ball

= mgh = 2 × 10 × 5

Potential energy = 100J

(ii) The kinetic energy of the ball just before hitting the ground is equal to the initial potential energy and is given by mgh

= 2 × 10 × 5 = 100J

(b) After the ball hits the ground and comes to a stop, mechanical energy is converted to heat and sound energy.

i

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