You push a small child on a swing at the park. As you do, energy and energy covert back and forth to each other.

When you push a small child on a swing at the park, the energies that convert back and forth to each other are potential energy and kinetic energy.

Here's the step by step explanation:

1. When the swing is at the highest point in its arc (either forward or backward), it has maximum potential energy because it is as high as it can get. Potential energy is the energy an object has because of its position relative to other objects, in this case the ground.

2. As the swing begins to descend, this potential energy starts to convert into kinetic energy. Kinetic energy is the energy of motion.

3. When the swing is at the lowest point in its arc, it has maximum kinetic energy and minimum potential energy. At this point, the swing is moving at its fastest.

4. As the swing begins to ascend again, this kinetic energy starts to convert back into potential energy.

5. The process then repeats, with energy continuously converting between potential and kinetic as the swing moves.

This is a basic example of the conservation of energy, where the total amount of energy in the system (the swing and the child) remains constant, it just changes forms.