Difference Between Kinetic Energy and Potential Energy
The kinetic energy and potential energy are the two energy states. The energy in the universe exists in many forms such as solar, thermal energy, electrical energy, magnetic energy, gravitational energy and chemical energy, etc. All the energy is basically categorized into two classes known as the kinetic energy and potential energy. There are differences between the two that can be beautifully illustrated with the help of an example.
Suppose you have a rubber ball in and you throw it in the air. The ball has initially zero potential energy as it is close to the ground and static. But it gets the kinetic energy as its speed increases. The kinetic energy decreases slowly due to the gravitation of the earth and finally it becomes zero when the ball stops in mid air. In its highest point in the movement, the ball has only potential energy by virtue of its height and the state of rest. Now the ball begins its journey back down and its kinetic energy begins to increase again while its potential energy decreases as it falls to the ground. Finally when it reaches land, it has the highest kinetic energy as potential energy has become zero.
A waterfall has both potential energy and energy kinetic as well by virtue of its height. When water is on top of a waterfall, it is full of potential energy. But when the water hits the bottom, it has only kinetic energy and no potential energy. This kinetic energy is used to generate electricity by converting kinetic energy into electrical energy. When you play with yo-yo, the ball has potential energy only when it touches your hand, but it gains kinetic energy when it comes down and the lowest point of any potential energy was converted into kinetic energy . When the ball goes up again, its kinetic energy is again transformed into potential energy.
It is clear from the above example that the kinetic energy is the energy an object possesses due to its state of motion. In fact, the word kinetic has its origins in the Greek word kinesis that means movement.
Potential energy is the other energy an object possesses due to its state of rest. It is also known as the energy restoration. All objects have a tendency to return to their position of rest as the work of energy against any potential displacement force. It is because of the gravitational force of the earth. If there was no gravitational force, a ball dropped in the air would never return to land and continue his journey right up.
The energy can not be created or destroyed. It only changes its forms which is why the kinetic energy is converted into potential energy and vice versa.