Question

Illustrate the low of conservation of mechanical energy in the case of a ball dropped from a cliff of hight H

Answer 1

Answer:

Total mechanical energy at height, H

EH=mgH

Let vh be velocity of the ball at height h (=34H) .

∴ Total mechanical energy at height h ,

Eh=mgh+12mv2h

According to law of conservation of mechanical energy,

EH=Eh;mgH=mgh+12mv2h

vh2=2g(H−h)

Required ratio of kinetic energy to potential energy at height h is

KhVh=12mv2hmgh

=12m2g(H−h)mgh=(Hh−1)=13