Formula for Kinetic Energy- Definition, Types, SI Units and Examples

Published by Kabir Chibber on

Most of us are familiar with energy and its various forms. As the globe shifts toward a more sustainable way of life, it is natural to wonder, “What is energy? “What are the many types of energy?” One sort of energy involves a body’s mobility, which is called Kinetic Energy. Let’s take a look at what Kinetic Energy is, the formula for Kinetic Energy, its types, examples, and SI units:

What is Kinetic Energy?

Kinetic energy is a form of energy that is in an object when it moves.

It is present in every object when it moves from particles, atoms, and molecules to an athlete running, a ball falling down, or a car traveling across a road. Kinetic Energy is relevant to body’s mass and square of body’s velocity.”

SI units:

Joules is the SI unit of energy, and Joules remains the SI unit for Kinetic energy too, although the motion caused by Kinetic Energy can be represented by meters per second (m/s), kilometers per hour (km/h), etc.

Formula for Kinetic energy

If a body of mass m starts moving with velocity v then the equation used to calculate the kinetic energy of mass is given as:

K.E = 1/2m v2

From the formula, it is clear that the velocity is more important for the kinetic energy of a body than the mass of the body that’s why a body having a smaller mass can also have high kinetic energy if it gets high speed.

Because the value of mass is always positive and the square of velocity is likewise positive, the kinetic energy of the body is positive, which means we obtain the most kinetic energy when the velocity is greatest.

The above formula can also be reformed to calculate the mass and velocity of the body.

v = √ (2K.E/m) and m = 2K.E /v2

Types of Kinetic Energy

On behalf of the motion, the kinetic energy is divided into the following three types.

Translational Kinetic Energy

  • Because translational motion includes linear, circular, and random motion, the energy carried by objects performing these motions is translational kinetic energy. 
  • Translational kinetic energy is, for example, the energy possessed by a plane flying in a straight line, the energy possessed by a butterfly during its zigzag motion, and the energy possessed by a stone connected to a string moving in a circular path. 
  • The formula of kinetic energy remains the same for translational kinetic energy as it is for general kinetic energy.

Rotational Kinetic Energy

  • Rotational kinetic energy is the kinetic energy possessed by bodies moving around their axis.
  • Basic examples of rotational kinetic energy include the energy carried by a spinning top, the energy of a rolling wheel, the energy of a rotating turbine, and the energy possessed by the rotational motion of a toy train.
  • The formula of kinetic energy changes when we deal with rotational motion. For rotating kinetic energy, the updated formula is as follows:

K.E = 1/ 2 I ω2

              Where “I” is the inertia of the body and ω is the rotational velocity of the body.

Vibrational Kinetic Energy

  • The kinetic energy that deals with the to and fro motion of bodies is called vibrational kinetic energy.
  • The energy of a simple pendulum, the energy of a sea-saw, and the energy of vibrating molecules are some examples of vibrational kinetic energy.
  • The formula of kinetic energy does not change in vibrational kinetic energy.

Examples:

Example 1: For Kinetic Energy of a body

A batsman hits a ball with a speed of 30m/s. Calculate the kinetic energy of the ball if its mass is 500g. 

Given data

Mass = 500g = 0.5kg

Velocity = 30m/s

To find

Kinetic energy = K.E =?

Solution: Manual method

The general formula to calculate kinetic energy is given as:

K.E = 1 / 2 mv2

Put the values in general formula.

K.E = 1 / 2 ×0.5 ×302

K.E = 450 / 2

K.E = 225J

The solution to the above problem has been computed by using the manual method.

To solve the difficulty above, you can use a kinetic energy calculator. It helps us to handle problems fast and effectively by using a scientific approach. The following process is used to compute the kinetic energy calculator.

Step 1: From the drop-down menu, select the physical quantity you want to calculate.

Step 2: Put the respective values and click on calculate button.

As a result, the above problem has been calculated in a very simple way.

 Example 2: For the mass of a body

With a velocity of 7m/s, a solid metal block slides effortlessly through the inclined path, gaining K.E of 150j. Calculate the block’s mass.

Given data

Kinetic energy = 1s50J 

Velocity = 7m/s

To find

Mass of body = m =?

Solution: Manual method

The general formula to calculate kinetic energy is given as:

K.E = 1 / 2 mv2

Put the values in general formula.

150J = 1 / 2 ×m ×72

150J = m / 2 × 49

150J = m / 2 × 49

m / 2 = 150 / 49

m = 3.06 × 2

m = 6.12kg

The solution to the above problem has been computed by using the manual method.

Conclusion:

From this article, it is clear that kinetic energy is important in not only in theoretical subjects but also plays an important role in activity-based problems. With kinetic energy elaborated, you now know that to find everything from thermal energy to electrical energy, we rely on kinetic energy.

Moreover, the type of kinetic energy depends upon the type of motion. In this article, we learned two methods to solve the kinetic energy problem one is the manual method and the other is the calculator method. You have the choice to use a kinetic energy calculator to fasten your longer calculations.

Other forces also act on the Earth directly to physically change it. One such force is endogenic force, which you can learn about here.

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Kabir Chibber

Hi, I am Kabir Chibber, the Primary editor of Kabducation.com. There is a good chance you have read a few articles from me if you have been to Kabducation. To contact me for questions or anything else, use this email ID: [email protected]

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