If a boulder pushed down a hill has 20 Joules of potential energy at the top of the hill, how much kinetic energy does it have once it is at the bottom of the hill?

A5 kg block of fe is dropped into a very large vat of water. the fe and water initial temperatures are 95 and 25 c, respectively. the fe final temperature is 25 c and the water can be treated as a thermal reservoir,. treated as a thermal reservoir take the water to be the system and determine the entropy generation. report vour answer in kj/k.