The experiment that I am going to describe showed that heat is just another kind of energy like kinetic energy or potential energy.

Let us begin by thinking about what scientists mean by energy and work. One kind of work is when we move a heavy object against gravity. That is, we lift it up through a height. This means that it now has a kind of energy that we call potential energy. When we let the object fall down, it can do work for us and changes the work back into moving or kinetic energy.

But what happens when an object hits the ground? Surely, it has stopped moving? Does this mean that it has lost its energy? Has the energy somehow disappeared?