Question

A boy drops a ball of mass 500 g from a height 10 m. Ignoring the effects of air resistance
Calculate the kinetic energy it possess at point 3 (i.e., just before it reaches the earth
(g = 10 m s-2).​

Answer 1

Mass of the Body = 500 g = 0.5 kg

Height = 10 m.

Acceleration due to gravity = 9.8 m/s².

Using the Formula,Potential Energy = mgh

= 0.5× 9.8 × 10 = 49 J.

Now, By the law of the conservation of the Energy, Total amount of the energy of the system remains constant.

∴ Kinetic Energy before the body reaches the ground is equal to the Potential Energy at the height of 10 m.

∴ Kinetic Energy = 49 J.