Notion of Potential Energy

Introduction

William Rankine, a 19th-century Scottish engineer and physicist, coined the term “potential energy.” There are various different types of potential energy, all of which are linked to different sorts of forces. Potential energy is the energy that an object has as a result of its position in relation to other objects.

The position of an object, as we all know, can lead it to store energy. When you draw a bow and arrow, the bow stores some energy that is responsible for the kinetic energy generated when you release it. 

The definition of potential energy is as follows: The energy that an item has as a result of its position in respect to other objects, internal tensions, electric charge, or other causes is referred to as potential energy.

For example, when a demolition machine’s heavy ball is held at an elevated position, it stores energy. Potential energy is the name given to this stored positional energy.

Similarly, when a spring is pushed from its equilibrium position, it gains energy, which is observed by us from the stress in our hand when we stretch it. Potential energy is defined as a type of energy that results from a change in its location or state.

There are other types of potential energy that exist. 

The energy trapped between the plates of a charged capacitor is known as electrical potential energy. Chemical energy, or a substance’s ability to produce work or emit heat by changing its composition, can also be thought of as potential energy coming from the mutual forces between its molecules and atoms. Nuclear energy is a type of potential energy as well.

Potential Energy Unit

The units for gravitational potential energy are the same as those for kinetic energy: kg m² / s²

• All energy is measured in Joules and has the same units – kg m² / s² (J).

Potential Energy Formula

The force acting on two objects determines the formula of potential energy formula. The formula for gravitational force is:

Where W = m×g×h = mgh

• The mass in kilogrammes is denoted by m.
• The acceleration owing to gravity is denoted by the letter g.
• The height in meters is denoted by h.

Types of Potential Energy

Along with kinetic energy, potential energy is one of the two basic types of energy. 

Potential energy can be divided as follows:

1. Potential gravitational energy

The energy possessed by an object as it rises to a particular height against gravity is known as gravitational potential energy. With the following example, we will formulate gravitational energy.

Consider the mass of an item with a mass of m at a height of h from the ground.

As we all know, the force required to lift an object is equal to the object’s m×g

A certain amount of work (W) is done on the object as it is elevated against gravity.

Force displacement = work done on the object.

Because the work done on the item is equal to mgh, the energy gained by the object equals mgh, which in this case is the potential energy E, according to the rule of conservation of energy.

E of an item elevated from the ground to a height of h = mgh

The gravitational energy of an object is determined by its displacement, or the difference between its height at the beginning and the final height. As a result, the path taken by the object to achieve its current height is ignored.

2. Potential energy of elasticity

Elastic potential energy is the energy that is held in items such as rubber bands, trampolines, and bungee cords which can be compressed or stretched. The more elastic potential energy an object has, the more it can stretch. Many items are expressly intended to store elastic potential energy, as shown in the following example.

• A toy plane is powered by a twisted rubber band.
• The bow of an archer is stretched out.
• Just before a diver dives in, a diver’s board is bent.
• A wind-up clock’s coil spring.

An object that accumulates elastic potential energy has a high elastic limit, yet all elastic objects have a load limit. The object will not return to its original shape if it is deformed beyond the elastic limit.

The following formula can be used to compute elastic potential energy:

U = ½ kx²

The elastic potential energy is denoted by U.

The spring force is denoted by the letter k. 

The string stretch length in meters is the constant x.

3. Chemical potential energy

Gasoline is a useful fuel source because of its chemical makeup (molecular arrangement). Molecules make up all non-living and living entities, from vehicles to zebras. It takes energy to create and hold these molecules together. 

Chemical potential energy is the energy held in molecules. Bonds are broken and repaired during combustion, resulting in new products. The stored energy in gasoline is released when it is burned (combustion). Chemical bonds are broken and rebuilt during combustion, generating energy and converting gasoline into byproducts such as water and carbon dioxide.

Many examples of chemical potential energy being transformed to kinetic energy and then being used to do work exist. Our bodies use the chemical energy from food to move. Chemical energy is employed in a lit firecracker to generate a loud noise and disperse bits of the firecracker all over the place.

4. Electrical potential energy

When positive and negative electric charges are separated from one another, such as in a battery, there is electrical potential energy that exists. 

When you turn on a battery-operated item, such as a flashlight or a toy, the electrical potential energy contained in the battery is turned into sound, mechanical action, thermal energy, and light. A rotating generator of a power plant, hydroelectric dam, or windmill maintains the electrical potential energy for the electrical equipment that is connected. As long as the sun shines on it, a solar cell stores electrical potential energy in the same way as a battery does.

5. Nuclear potential energy

The energy stored in the nucleus of atoms is known as nuclear potential energy or nuclear energy. Due to their positive charge, the protons in a nucleus have very strong repulsive forces against each other. In turn, the protons are held together by the strong forces exerted by the neutrons that make up a nucleus. 

Nuclear fission (the splitting of a large nucleus) and nuclear fusion (the joining of tiny nuclei into a larger nucleus) both overcome these tremendous pressures and release energy as a result. Individual nuclei release very little energy, but massive numbers of nuclei can release enormous quantities of energy, as proven by the energy produced by nuclear reactors (fission) and the sun (nuclear fusion).

6. Thermal energy

Thermal energy is produced by the movement of the molecules that make up an object or a substance, as well as the kinetic energy associated with this movement. Since they have a temperature greater than absolute zero, all objects (even the cold ones) have thermal energy. 

The temperature of an object can be used to discover evidence of thermal energy.

The term “heat” is frequently used to refer to thermal energy, despite the fact that it is technically wrong. There is a significant distinction between the two in scientific terms. 

The kinetic energy of molecules within an object is referred to as thermal energy. The transmission of energy between two objects is known as heat. Since heat is a more common concept, it is frequently utilised for simpler comprehension.

Conclusion

Potential energy can be turned to kinetic energy, which is the energy of motion, and then to other forms like electric energy. As a result, the water behind a dam travels to lower levels via turbines that drive electric generators, creating electricity as well as some useless heat energy due to turbulence and friction.

Potential energy was previously included with kinetic energy as a form of mechanical energy in order to determine the total energy in gravitational systems as a constant.