Question

A mass of 10 kg is dropped from a height of 50 cm
write its kinetic energy .
velocity just reaches its ground.
the velocity depend upon the mass of the object.

Answer 1

Dear Student

Given, mass of the object, m = 10 kg , Height, h = 50 cm= 0.5 m
As potential energy is given by PE = mgh
= 10 x 10 X 0.5 = 50 J
(i) 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
(ii)As , we know KE = 50J
so by using velocity equation

v²-u²=2gh
v²- 0=2 X 10 X 50 X 10^-2
so the velocity V=$\sqrt{10}$ m/s
Regards