A mass of 10 kg is dropped from a height of 50 cm. Find its

(i) potential energy just before dropping.

(ii) kinetic energy just on touching the ground,

(iii) velocity with which it hits the ground.

# A mass of 10 kg is dropped from a height of 50 cm

**prasanna**#1

**prasanna**#2

Given, mass of the object, m = 10 kg , Height, h = 50 cm= 0.5 m

(i) As potential energy is given by PE = mgh

= 10 x 10 X 0.5 = 50 J

(ii) From law of conservation of energy,

total energy of the ball just before dropping = total energy of the ball just on touching the ground => KE + PE of ball just before dropping

= KE of ball just on touching the ground = KE= 50 J

(iii)As , we know KE = 50J

so, 1/2 m ${{v}^{2}}$ = 50

${{v}^{2}}$ = 50 x 2/10 = 10