Gravitational Potential Energy It is called potential energy because it has the potential to do work. If the soccer ball is raised to a certain height, at the top, before it gains Kinetic Energy, it has the Potential stored that it will be used once it starts to move.

Lifting a ball into the air before dropping it gives it a type of energy called ‘potential energy’ – which means the ball has the potential to do some work. When you drop the ball, it gains ‘kinetic’ energy (the energy of motion) and loses its potential energy.

Explain why a thrown football has both potential and kinetic energy. The combined energy is called mechanical energy.

Potential energy, stored energy that depends upon the relative position of various parts of a system. A spring has more potential energy when it is compressed or stretched. A steel ball has more potential energy raised above the ground than it has after falling to Earth.

Potential energy is greatest when the most energy is stored. This could be when an object reaches its highest point in the air before falling, a rollercoaster just before it drops, or when a rubber band is stretched as far back as possible before it snaps. Potential energy is then converted to kinetic energy.

When an object has the LEAST potential energy is when it has the MOST kinetic energy.

Kinetic energy is highest at point B and potential energy is lowest.

When an object falls, its gravitational potential energy is changed to kinetic energy. You can use this relationship to calculate the speed of the object’s descent. Gravitational potential energy for a mass m at height h near the surface of the Earth is mgh more than the potential energy would be at height 0.

The factors that affect an object’s gravitational potential energy are its height relative to some reference point, its mass, and the strength of the gravitational field it is in.

The primary relationship between the two is their ability to transform into each other. In other words, potential energy transforms into kinetic energy, and kinetic energy converts into potential energy, and then back again.

Since the gravitational potential energy of an object is directly proportional to its height above the zero position, a doubling of the height will result in a doubling of the gravitational potential energy. A tripling of the height will result in a tripling of the gravitational potential energy.

Rivers are strictly kinetic energy at work. The water is constantly moving, and all that motion is constantly creating kinetic energy. The only time a river could have potential energy is if it is dammed, with the artificial reservoir storing energy to be used when needed along a hydroelectric dam.

If only internal forces are doing work (no work done by external forces), then there is no change in the total amount of mechanical energy. The total mechanical energy is said to be conserved.