KINETIC ENERGY�(Unit 5,9^th Standard Physics)

Ms PRAVEENA K

4^th SEMESTER B.Ed PHYSICAL SCIENCE

NSS TRAINING COLLEGE OTTAPALM

What is Energy?

Energy is the capacity to do work

​

Work W= Force * Displacement

If F is the force and d is the displacement, W=F*d

Unit of work is Joule

Displacement

Box moved from 1 to 2 by applying force

Force

1

2

Different forms of energy

Mechanical Energy

�When a toy car hits a ball�

​

Try to answer these questions

What happens to the ball when the car hits?

Is there any force applied on the ball?

Is there any work done on the ball?

How did the car get the energy to hit the ball?

​

​

Answers:-

• The ball got displaced when the car hits
• Force was applied on the ball by the car
• Yes, work was done on the ball by the car
• Work done= Force * Displacement

W=F*d

​

• The car get energy to hit the ball by its motion.

Kinetic Energy Definition

• The energy possessed by a body by virtue of its motion is the kinetic energy.
• Example- Car moving in a road

​

Examples of objects possessing kinetic energy

Flying aircraft

Bullet fired from gun

Running animal

Examples of objects not possessing kinetic energy

Dog sleeping

Vehicles parked

Boy standing

Factors affecting kinetic energy

When ball rolling down from slopes of different heights hit a car at rest on the bottom of slope, the velocity of motion changes in different cases and motion of car will be more when velocity is high.

Factors affecting kinetic energy

Ball 1

Ball 2

Paper cups

When paper cups are strike with balls of different mass, the cups have more displacement when mass of ball is high.

Factors affecting kinetic energy

Thus the two factors affecting kinetic energy are

​

1. Velocity of the moving body
2. Mass of the moving body

Equation for kinetic energy �

Thank you