It is observed that water at the foot of a waterfall is of different tampreature than that at the top . Why?

Explanation

On falling form a height, the potential energy of water is converted tnto its kinetic engergy slowly and is maximum at the foot of the hills. The velocity of the water , which is maximum at the foot of the waterfall on collision with the bottom, is reduced almost to zero. This loss of kinetic energy is compensated in the form of heat energy, raising the temperature of the water at the foot of the waterfall.