Kinetic Energy Definition

When the work is done on the object, the energy is transferred to the object, and the object moves at a constant speed. The energy that is transferred to the object is called kinetic energy. To accelerate any object, we have to apply the force on the object. We can do any type of work by applying force. In this article, we are going to discuss kinetic energy and its types.

What is Kinetic energy?

The kinetic energy of an object is defined as the energy that it possesses by its motion. If we want to move any object, we need to apply a force on the object. When the work is done on the object, the energy is transferred to the object at a constant speed. The energy that is transferred to the object is called kinetic energy. It depends on the object's mass and speed.

The kinetic energy may also be transferred between the objects and transformed into other types of energy.

Units for Kinetic energy

The SI unit of kinetic energy is Joule, which is equal to 1 kg.m².s^-2, and the CGS unit is erg.

Formula for Kinetic energy

The basic formula for calculating kinetic energy is:

KE = ½ mv²

In this formula, KE is the kinetic energy, m is the object's mass, and v is the object's velocity.

How can we calculate the Kinetic Energy?

The kinetic energy equation can be calculated by the simple method of computing the work (W) done by force (F). If the body mass (m) moves to a distance (d) on the surface by applying a force parallel to it, the work done will be:

W = F.d = m.a.d

This equation's acceleration could be substituted by the initial velocity (vi), final velocity (vf), and the distance d. It can be obtained from the kinetic energy equations of the motion.

W = m.a.d

= m.d.(v²_f-v²_i/2d)

= m.(v²_f-v²_i/2d)

= ½.m.v²_f - ½.m.v²_i

After simplifying the equation, we will get

K.E = ½mv²

We can also say that the total work performed on the object is equal to kinetic energy change. The equation can be written as follows:

W_net=ΔK

This equation is also known as the work-energy theorem.

Types of Kinetic Energy

There are several types of Kinetic Energy, such as radiant, thermal, electrical, mechanical, and sound energy.

Radiant Energy

It is defined as the energy of electromagnetic waves or light energy that can move through space. It is also known as electromagnetic energy.

The following are the various examples of kinetic energy:

• X-rays
• ultraviolet light
• gamma rays
• microwaves
• infrared radiation
• radio waves.

Thermal Energy

Thermal energy is defined as an object's internal energy due to the motion of atoms and molecules. The object's thermal energy depends on the kinetic energy of atoms and molecules. It is also known as heat energy.

The following are the various examples of thermal energy::

• Heated swimming pool
• Hot springs

Electrical Energy

The energy of the traveling electron is called electrical energy. All the objects are made of tiny particle that is called atoms. Atoms are made with other small particles, including neutrons, protons, and electrons. The electrons are present in the atom that moves continuously around the nucleus of the atom. Electrical energy is derived from the positive and negative charges of free electrons.

The following are the various examples of electrical energy:

• Electric bulb
• Lightning
• Batteries

Mechanical Energy

It is defined as the sum of kinetic and potential energy. This energy cannot be generated or destroyed but can be converted from one form to another.

The following are the various examples of mechanical energy:

• A moving car
• Orbiting a satellite around the earth

Sound Energy

Sound energy is the energy that is produced by the vibration of an object or sound source. This energy can pass through any medium by moving energy from one particle to another.

The following are the various examples of sound energy:

• Horn
• Alarm
• Drum
• Crackers
• Tuning fork