A12.0 kg rock slides off the edge of a bridge and falls into the water 25.0 meters below. what is the kinetic energy of the rock just as it hits the water?

During the fall, all the initial potential energy of the rock 

has converted into kinetic energy of motion

where h is the initial height of the rock, m its mass, and v its velocity just before hitting the water. So, for energy conservation, we have

and so we can find the value of K, the kinetic energy of the rock just before hitting the ground:

Rain is pulled by gravity which is a non contact force