Potential Energy

What is Potential Energy?

Potential energy is the energy possessed by a body owing to its position, shape, and configuration. Work done on a body by any conservative force is stored in the form of potential energy in the body.

A conservative force is a force where the work is done depends on the starting and the ending points, but not on the path in which the work is done.

How does a body attain potential energy?

Energy, as explained in Physics, always manifests from one form to another. It can neither be created nor be destroyed. This is the law of conservation of energy. This applies to potential energy too.

Potential energy is imparted to any object that is at a certain height from the ground. Besides a body under the influence of other forces also contains potential energy. It means potential energy is of various types depending on what caused it. Let us understand this now.

Potential energy is measured in joules (J). There are various forms of potential energy.

Potential energy due to height from the ground

Any object that is at a height from ground level has potential energy. Consider a body of mass ‘m’ kilograms at a height ‘h’ meters above the ground. Then the potential energy stored in it given by m*g*h, where g is the acceleration due to gravity, 9.8 m/s².

How is this possible? Just because of the height, how the body is obtaining energy? Well, the magnetic field of the earth and the height from the ground and its mass combine to give it the potential energy. It means in this case the gravitational energy is manifesting into potential energy. Hence, sometimes this potential energy is also termed as gravitational potential energy.

Also, the greater the mass and the distance from the ground level, the higher is the potential energy contained by the body.

A good example of the usage of potential energy imparted by the virtue of height is water stored in a dam. This energy is used to run a turbine and generate electricity.

Potential energy due to the elastic property

Some objects such as rubber bands, springs that have elastic nature. When they are stretched or compressed, they store energy in the form of potential energy. This phenomenon is governed by Hooke’s law.

Now, where does this energy come from to a spring or rubber band? When you press or stretch a rubber band, you apply a certain amount of force. The amount of force required is given by F = k * x, where K is a proportionality constant called spring constant and x is the displacement by which you either stretch or compress the body. This force does its work and this work is stored in the form of potential energy in the elastic body. Thus, here too, we can observe the manifestation of work done into energy stored. The value of potential energy thus stored in the spring is given by ½ kx².

Potential energy due to atomic bonds

We know that all atoms and molecules are bound by attractive forces. These atomic forces impart the chemical energy to the compounds. When these chemical compounds are heated or given any other form of energy such as light, heat, magnetic or heat, this chemical energy is converted into potential energy.

Is it possible that potential energy is negative?

We have studied in kinetic energy that for any given body kinetic energy is always positive. In the case of potential energy, the value can be negative too.

Consider this scenario. You are moving an object upward to a certain height. As always gravitation tries to pull it downward, it means a negative force is acting on it. Thus the body at a certain height is said to be having negative potential energy (-mgh).

Note that when the same body is left to fall from that height, this negative potential energy gets converted into kinetic energy and thus is considered positive.

What are examples of potential energy?

Due to the virtue of gravitational potential energy.

• A mass such as a book, rock or a bag kept at a certain height from ground
• A child on the top of a slide
• Water at the top of a waterfall
• Fruit ready to fall onto the ground
• A swing at its topmost position

Due to the virtue of elastic property

• A stretched catapult
• A stretched spring in a pinball machine
• A yoyo before it is released
• A compressed spring in a clock

Due to the virtue of chemical energy

• Dynamite ready to blow
• A carbonated drink before it is opened for the first time
• Gasoline before it is combusted

Characteristics of Potential Energy

• Potential energy is stored energy
• From where is the object situated at a height obtaining energy? From the work done by the gravity on it. Similarly, how is the energy being stored in a stretched rubber band or a compressed spring? Because of the force that is externally forcing it. This means, the energy is being stored in the object as long as the force is acting, and this energy can be used later in another form once the influence of the force is removed. This is what is happening in the case of stored water in a dam, or stretched arrow and bow, or chemical energy being used in atomic explosions.
• Potential energy is scalar
• Energy, in any form, is a scalar quantity. Potential energy is thus a scalar quantity, which can be positive, negative or zero.
• Potential energy is not transferrable
• Potential energy cannot be transferred from one object to the other. Consider this example. Two bodies are at different heights from the ground, and thus have different values of potential energy. How can you transfer the potential energy from one body to other? You can just change the heights by yourself, which means some amount of work is being done externally by you. Thus, potential energy cannot be transferred but only can be used at a later point in time.
• Potential energy changes its form
• By its natural property, energy always changes from one form to another. This holds for potential energy too. Chemical energy that you obtain from atoms is a form of potential energy. The energy obtained by burning gasoline is a form of potential energy. The water gushing out of dams when gates are released is a kinetic form of potential energy. Electric, thermal, kinetic, nuclear, mechanical, sound and electromagnetic energies are all other forms of potential energy.

The law of the Conservation of Energy is already known — viz., that the sum of all the energies of the universe, actual and potential, is unchangeable.
William John Macquorn Rankine

Facts about potential energy

• For an object of a given mass, the potential energy stored is directly proportional to its height from the ground. It means you double the height at which a body is placed from the ground, its potential energy also doubles.
• A Scottish engineer and Physicist coined the term ‘potential energy’ for the first time during the 19th century. However, the concept dates back to the era of Aristotle.
• The uniqueness of potential energy is that it can be stored and used at a later point in time. Hence the name ‘potential’.
• Originally, potential energy and kinetic energy together were considered to comprise mechanical energy. This consideration helped in calculations where gravitational energy was considered constant.
• The energy stored in the form of potential energy is completely recoverable.
• Potential energy does not depend on the environment of an object. It only depends on the work done on it by the force in the past.

How CalculatorHut’s online free potential energy calculator helps you?

CalculatorHut is a huge library comprising of 100+ scientific, health, finance and other calculators specifically designed to make calculations easy for every type of calculation. It is a go-getter tool for students, professionals, finance enthusiasts, health-conscious people, and everyone who deal with numbers in their day to day life.

Potential energy is an indispensable concept for any student of chemistry and physics. Potential energy calculator is one of the free online calculators of CalculatorHut, which is specifically designed to make potential energy calculations simpler. You can calculate any parameter of potential energy formula – mass, height, and potential energy, using CalculatorHut’s online free potential energy calculator within no time.

Wait, we have more! CalculatorHut’s other online free calculators across a wide range of calculators in math, physics, chemistry, finance, health, vehicle, and others are user-friendly and simple to use too.

If you own a blog or website and wish to get any of our calculators embedded as widgets on your website, drop a word to us at calculatorhut@gmail.com, and we will design you the widget free!

CalculatorHut also has its app for free! With a simple click on the download button from the playstore, you have this huge library of calculators in your pocket! Yay! It’s simple, isn’t it?? Yes. Because we aim at making scientific calculations simple and easy and want our users to simplify their life with our easy to use a calculator!

Enjoy your calculations!

The greater the contrast the greater the potential. Great energy only comes from a correspondingly great tension of opposites.
– Carl Jung.