Question

A 10 kg boulder rests at the edge of a 100 m cliff .
how much kinetic energy does the rock posses at the bottom of the cliff

Answer 1

The final kinetic energy will be equal to initial potential energy.(Law of conservation of energy).

PE⇒Potential energy

KE⇒ Kinetic Energy

So, initial PE=KE=mgh=10 x 10 x 100 = 10000 J

So kinetic energy = 10000 J