What is Kinetic Energy?

Kinetic energy is the energy an object possesses owing to its state of motion. The greater the speed of a body, the greater the kinetic energy. You could think of it as the energy of motion, i.e. the energy a body has because of its motion, or the amount of work a body is capable of doing because of its motion.

The Kinetic Energy Formula

The formula to find the kinetic energy is:

K.E=12mv2

Where:

KE kinetic energy.
m the mass of the object, in kilograms.
v is the velocity of the object in meters per second.

Breaking Down the Formula

Mass (m): This is the amount of stuff in the object. The more massive it is, the more energy.

Speed (v): This is, how fast it is moving; because this is squared in the formula. If something has its speed doubled, it increases its kinetic energy fourfold.

Units of Kinetic Energy

The SI unit of Kinetic Energy is joules (J). One joule is the energy exerted to be transferred when one Newton force moves an object at a one-meter distance.

Kinetic Energy Solved Examples

Below are Kinetic energy questions that help one understand where to use these questions.

Problem 1: A car is moving with a velocity of 10 m/s and has a mass of 250 Kg. Calculate its Kinetic energy.

Solution:

Given: Mass of the body m = 250Kg,

Velocity v = 10m/s,

Kinetic energy is given by

kinetic energy formula

Problem 2: A man is carrying a trolley of mass 6 Kg and possessing a Kinetic energy of 40 J. Calculate the Velocity with which he is running.

Solution:

Given: Mass, m = 6 Kg

Kinetic energy K.E = 60 J

kinectic energy formula

Therefore, the man is running with a velocity of 3.65m/s

The kinetic energy of something is dependent on both its mass and the velocity. This is again an important concept if the interaction of the moving bodies with the world around them is considered. Indeed, the formula K.E=12mv2 helps quantify the energy due to motion.

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