Types of Energy, Law of Conservation and Examples

Energy is the ability to do work. In Scientific term, Energy is defined as the quantitative property that is transferred to a body or physical system. Energy is divided into mainly two types: 1. Kinetic Energy and 2. Potential Energy. They are later divided into many types based on forms of energy such as light energy, gravitational energy, electrical energy, nuclear and many more.

Energy is defined as the ability of substances to do work. We often use the word “Energy” in our daily life. It exists in different forms. In this article, let us understand in detail about types of energy, the law of conservation of energy and various types of energy.

In this article, We have discussed the definition of Energy, its types, the law of Conservation of Energy, and many more.

Definition of Energy

It is a quantitative property that is used to perform work. One can define “Energy is the ability to do work”. Energy on the planet exists in different form. The Sun is considered as main source of energy on earth. Energy on the planet exists in different form. The Sun is considered as main source of energy on earth. According to Law of Conservation of Energy, Energy can neither be created nor be destroyed. It can be converted from one form to another form. Total energy remains constant in an isolated system.

What is Energy?

Energy is the capacity to do work or bring a change. One essential difference lies between kinetic energy, associated with motion, and potential energy, stored and ready to be released. For instance, a moving car possesses Kinetic Energy, while a stretched rubber band has potential energy. As objects and systems undergo changes, energy transforms from one type to another, contributing to the dynamic nature of the world. Energy takes on different forms, including heat, light, and sound, all of which impact our daily experiences.

Different Types of Energy

There are various types of energy depending on the way of force exerted. In physics, there are mainly 2 types of energy which are the following:

1. Kinetic Energy
2. Potential Energy

Types of Energy

Kinetic Energy

Kinetic energy is defined as the energy associated with an object’s movement. For example, a moving bicycle will exerts some force after a collision with other substances. That force is created due to stored Kinetic Energy.

Kinetic Energy

A simple example of Kinetic Energy is thermal energy, which is the constant and random movement of atoms or molecules within a substance. This movement generates the sensation of heat. The average thermal energy of a group of molecules corresponds to the temperature, and the exchange of thermal energy between objects is termed as heat. To calculate kinetic energy, we use the following formula:

K.E=1/2 mv²

where:

KE represents Kinetic Energy,

m is the Object’s Mass, and

v is its Velocity.

Different Types of Kinetic Energy

There are various forms of kinetic energy that can include radiant energy, thermal energy, sound energy, etc, which is discussed below:

1. Radiant Energy
2. Thermal Energy
3. Sound Energy
4. Electrical Energy
5. Mechanical Energy

Radiant Energy

Radiant Energy is that energy that travels as waves or particles, primarily through electromagnetic waves. One of the most common ways humans experience radiant energy is in the form of heat. To put more simply, radiant energy is one of the forms of kinetic energy that is a result of electromagnetic radiation, which is the energy that radiates from various sources to its surroundings. Example: visible light, the warmth of incandescent bulbs when you turn on an incandescent light bulb. Sunlight is another example of radiant energy, delivering heat and light to Earth.

Thermal Energy

The key difference between radiant energy and Thermal Energy is that the thermal energy focuses on the activity level among atoms and molecules within an object. In simple terms, it’s about how fast the particles are moving which is related to the movement of atoms and molecules within a substance. In any matter, the atoms as well as molecules that form it are always constantly moving. When any substance gets heated then its temperature naturally rises, and as a result we can see these particles move faster and also bump into one another. Example: geothermal energy, the warmth generated by a running engine. Also, when you heat up pizza in an oven, the molecules in the pizza move rapidly, which shows thermal energy.

Sound Energy

Sound Energy is that type of kinetic energy that travels through a medium and thereby reach our ears. These vibrations are thereafter converted into electrical signals by our ears, which are then translated into sound by the brain. All types of materials for ex. gas, liquid, as well as solids transmit the sound energy as waves. As a result, sound energy is produced due to the vibrations that go or move through something.

Electrical Energy

Electrical Energy is another kind of kinetic energy and it is associated with the movement of electrons. The flow of negatively charged electrons in a conductive material is what we commonly call as being electricity. Electrical energy is a very basic and fundamental form of energy that powers our daily devices, appliances, etc. In other terms, electric energy is the ability of the electrical circuit to produce some work by creating an action.

Mechanical Energy

Mechanical Energy is that form of kinetic energy which is related with the movement of objects. It includes both potential energy and kinetic energy. To say in simple terms, it is the energy related to the mechanical movement of objects and is often called as the motion energy. This kind of energy is the total kinetic energy as well as the total potential energy a body can possess.

Potential Energy

Potential Energy is a measure of the energy stored in a material. Potential Energy is defined as the energy stored by an object due to its arrangement, state or position. Potential Energy is different from kinetic energy in many ways like, kinetic energy is the energy of the motion of an object, while potential energy is the stored energy of the object. For example, imagine a Bicycle on the top of mountain. So the bicycle at top of mountain having a form of energy called Potential Energy. This energy will be transferred into Kinetic Energy when we will start moving down from mountain to bottom at surface.

PE = mgh

where:

PE = potential energy,

m = mass of the object,

g = acceleration due to gravity, and

h = height or vertical position of that object.

Potential Energy Diagram

Both potential energy and kinetic energy form mechanical energy. Here is the derivation of Sum of Kinetic and Potential Energy.

ME = PE + KE

where:

ME = Mechanical Energy,

PE = Potential Energy and

KE = kinetic energy.

Different Types of Potential Energy

There are various types of Potential Energy. Some of the important types of Potential Energy are described below:

1. Gravitational Potential Energy
2. Elastic Potential Energy
3. Chemical Potential Energy
4. Electric Potential Energy

Gravitational Potential Energy

Gravitational Potential Energy is the energy stored in an object due to its vertical position or height. An object positioned at a greater height holds more gravitational potential energy compared to one closer to the ground. In simple terms, this kind of energy is associated with gravitational force of the earth. When some object falls from a point to some other point below within a gravitational field, then it decreases the total gravitational potential energy.

Example of Gravitational Potential Energy

Examples of Gravitational Potential Energy include the following:

• River water at the top of a waterfall
• A book on a table before it falls
• A car parked at the top of a hill

Elastic Potential Energy

This type of potential energy is stored when an external force deforms an elastic object. Such deformation can involve compression, stretching, or even twisting. This kind of energy is reversible and so when some force is applied, the elastic compresses but also recovers to the original shape as a result of elastic energy. In simple terms, when an object is stretched more, then it stores higher elastic energy. But all items have their limit, and so when deformed more than the elastic limit, they will are permanently deformed.

Example of Elastic Potential Energy

Examples of Elastic Potential Energy include the following:

• A coiled spring
• The string of an archer’s bow when pulled back
• A stretched rubber band

Chemical Potential Energy

Chemical Potential Energy is defined as the energy stored in the chemical bonds of the substance. To understand more clearly, the molecules in a substance are connected with the help of or using chemical bonds. The chemical reactions aid in transforming this energy from one form to the other form.

Example of Chemical Potential Energy

Examples of Chemical Potential Energy include following:

• Energy in green leaves before the sun activates photosynthesis
• Gasoline before ignition
• Fireworks before they are launched

Electric Potential Energy

Electric Potential Energy represents the energy required to move an electric charge against an electric field. In other words, this is that energy which is related to the position of charged particles in electric field. The electric potential energy is there in objects due to their electric charge. Also, this energy is present between 2 bodies in space as a result of the exerted charge which is obtained from the force.

Example of Electric Potential Energy

Examples of Electric Potential Energy include following:

• An incandescent light bulb when turned off
• A radio tower that is not operating
• A turned-off black-light
• A television before it is switched on

Units of Energy

The S.I. unit of energy in Joule. However, energy can also be measured using various other Units of Energy that do not belong to the International System. These units include ergs, calories, British Thermal Units (BTUs), kilowatt-hours (kWh), and kilocalories. When expressing energy in SI units, conversion factors are needed for these alternative units.

1 Joule of Energy is defined as the energy exhausted by applying a force of one newton through a distance of one meter.

Law of Conservation in Science

Energy can neither be created nor be destroyed. It can be transferred from one form of energy to another. Hence the total energy in a system will be constant. There are few ways through which the form of energy is converted to another:

• Mechanically – By the action of force

• Electrically – Electrically

• By Radiation – By Light waves or Sound waves

• By Heating – By conduction, convection, or radiation

Law of Conservation of Energy

The following is the universal law of conservation of energy:

The Law of Conservation of Energy states that “Energy can neither be created nor destroyed, but can only be converted from one form to another. The total energy remain constant in a closed body.”

Energy Transfer

Energy Transfer occurs when energy moves from one object or system to another without changing its form. A common example is the transfer of heat energy. When you touch a warm cup of tea, heat energy is transferred from the tea to your hand. Similarly, when you plug in a device and it starts working, electrical energy is transferred from the power source to the device.

Energy Transformation

Energy Transformation involves changing one form of energy into another. As an example, consider a Hydroelectric Power plant. It converts the potential energy of stored water at a height into kinetic energy as the water flows down. The kinetic energy is then transformed into electrical energy as it turns turbines connected to generators. In our daily lives, a flashlight transforms chemical energy stored in batteries into light energy when you turn it on.

Conclusion

Looking ahead, the role of energy in shaping our future is undeniably crucial. As the global demand for energy continues to surge, there is a growing imperative to transition towards sustainable and Renewable Sources. The future of energy lies in harnessing the power of sunlight, wind, and other eco-friendly alternatives, not only to environmental impact but also to ensure a resilient and secure energy infrastructure.

Advancements in technology and a collective commitment to cleaner energy solutions pave the way for a future where our energy needs are met without compromising the health of our planet. Moreover, Embracing cleaner and more efficient energy sources is not just an environmental responsibility but a strategic move towards a more sustainable and equitable future for all.

Related Resources:

• Definition, Types, Examples, Work Energy Theorem
• Different Types of Energy Storage
• Potential Energy – Definition, Formula, Examples
• Conventional Energy Sources

Types of Energy – FAQs

What is energy?

Energy is a quantitative property that can be transferred from an object to perform work. It is the ability to do work. The SI unit of energy is Joule.

What are the different types of energy?

Energy is broadly categorized into two types: Kinetic Energy and Potential Energy. Kinetic energy is associated with the motion of objects, while potential energy is the energy stored in an object or system.

What is kinetic energy and how is it calculated?

Kinetic energy is the energy an object possesses due to its motion. It is calculated using the formula where m is mass and v is velocity.

What are some examples of kinetic energy?

Examples include a moving wrecking ball, the random bouncing of atoms or molecules (thermal energy), and the flow of electrons in electrical energy.

What is potential energy and how is it calculated?

Potential energy is the energy stored in an object due to its position or arrangement. It is calculated using the formula Potential Energy=m×g×h, where m is mass, g is the acceleration due to gravity, and h is height.

Can you give examples of potential energy?

Examples include a book on a shelf (gravitational potential energy), a stretched rubber band (elastic potential energy), and chemical energy in a battery.

What is the law of conservation of energy?

This law states that energy cannot be created or destroyed, only converted from one form to another. In a closed system, the total energy remains constant.

What is energy conversion?

Energy conversion is the process of transforming energy from one form to another, like mechanical energy to electrical energy.

What is the commercial unit of energy?

The commercial unit of energy is the Kilowatt-hour (kWh).

Can energy be stored?

Yes, energy can be stored in various forms, such as chemical energy in batteries, potential energy in elevated objects, or thermal energy in hot substances.