Potential Energy: Understanding Forces Acting Upon a Body

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In common speech, when I say that you have got potential, that means to say that you are capable of doing something, though you are not attempting it or haven’t started the process of doing it yet. Therefore in a way it refers to some hidden capacity or talent within you which is waiting to be tapped. This could be by virtue of your certain qualities such as singing talent, a genius brain, or a healthy body. In strict scientific terms the word Potential Energy has a similar meaning

The Potential Energy

Similar to the description above, potential energy refers to the energy stored within a body by virtue of its position where some sort of force it trying to bring the body to a different position. Take for example a football which is held high in the air with your hand. Now the gravitational force is trying to pull it down and change its position to ground level. Hence this force creates a potential energy within the football which can make it move downwards.

Similarly, there could be potential energy stored within a body in other situations such as the body being elastically deformed so that a force is trying to push the body back to its original shape. Similarly there can be a number of situations and various kinds of potential energies associated with the body.

You must have realized by now that the potential energy is only stored as a virtue of an opposing force. This force was trying to resist the body to move into that position in the first place and hence the work done in moving it from the original position to the final position is stored as potential energy. This is exactly in tune with what we learned in the previous article – that energy cannot be created or destroyed but can only change forms so I hope you are getting an idea of this energy concept by now.

In fact, batteries and cells that are used to run various equipment such as watches, toys, remote-controls, etc all the use the concept of electrical potential energy which is stored in the cells and cause the current to flow across the circuit in the form of electrons. This flow of electrons makes the device work.

Mathematically the potential energy (PE) is measured as a product of the mass of the body (m), its height relative to ground level (h) and the acceleration due to gravity (g). The equation is written as

PE = mgh

As you can make out from this equation that the higher a body goes, the more is its potential energy. So logically, if you take a body in outer space it should have an immense potential energy isn’t it? But then you are forgetting one thing that the factor of “g” has to be taken into account which is zero in outer space. So if energy is conserved, where has all the energy gone, which was used to propel the football into space?