If 10kg mass is dropped from a certain height,hits the ground with speed 10m/s. The height will be. Ans=5m. plz explain it?

Take g = 10 m/s²

Initial speed, u = 0 m/s
Final speed, v = 10 m/s
Acceleration, a = 10 m/s²
Height, s = ? m

v² = u² + 2as
10² = 0² + 2 × 10 × s
20s = 100
Height, s = 5 m

Kinetic energy of mass as it hits the ground = ½mv² = ½ * 10 * 10² = 500 joules

By conservation of energy, that 500 J must have been the gravitational potential energy of the object before it was dropped.

Gravitational potential energy = mgh
Therefore:

500 J = 10 kg * 10 m/s² * h
500 = 100h
h = 5 m