Age has many ways in affecting balance, one it changes the amount of energy needed so that the body won't be able to do things and task it ones could and two age can lower your energy balance because...
things that use energy mean a higher demand for electricity (meaning a higher demand for coal burning power stations, which produce a lot of carbon dioxide, which add to global warming
Potential energy is storing energy like when you go up on a rollercoaster. When you go down, the potential energy is released as kinetic or motion energy.