Concept of Potential Energy

Potential energy is the energy an object has when it is at rest. If an object has potential energy, it tells us that the object could do some work. If we stretch a spring and hold it, we can feel that it is pulling itself but we are not letting it. The spring is not moving but the energy with which it is trying to come back to its normal position is called potential energy.

When we throw a ball high up in the sky, at the highest point it stops for a very tiny amount of time. At that moment, the ball is in the air and high in the air, it has the energy to come down to the ground, this energy is called potential energy.

We can observe, from the above examples, that potential energy is of 2 types:

1. Gravitational Potential energy

When an object is placed at some height from the ground, the gravity of the earth acts on it and the energy stored because of this is called Gravitational Potential Energy. Gravitational Potential energy depends on the mass of the object, gravity, and height of the object from the ground.

• If the mass of the object is more, then the potential energy of the object is more.
• If the height of the object from the ground is more, then the potential energy of the object is more.

2. Elastic Potential energy

When an object is stretched and is held at the stretched position, it tries to get back to its original position. The energy with which the object tries to come back is called elastic potential energy.

When we stretch a rubber band and hold it in that place. The rubber band tries to come back to its original position and we can feel it putting force to come back to its original form. This energy that the rubber band is having in the stretched state which tries to come back to normal form is called elastic potential energy and this energy is due to the elastic nature of the rubber band.

Every object which is elastic in nature, when stretched, has some potential energy that forces the object to come back to its original position.

QUIZ:

1.Potential energy is the energy an object has due to its ________?

• Speed
• Acceleration
• Position
• Length

2.Gravitational potential energy is the potential energy of an object based on its _________

• Weight and velocity
• Height and mass
• Speed and height
• Name of the object

3.A pendulum is swinging. It stops for a very little time at the corners and again continues to swing. When it stops at the corner what type of energy does it have?

• Potential energy
• Kinetic energy
• Heat energy
• No energy

4.A cricket bat is placed on the bottom shelf of the cupboard and then on the topmost shelf of the cupboard. In which place does the bat have more potential energy?

• Top shelf
• Bottom shelf
• In both places, the potential energy is the same
• Cannon tell because we don’t know which company the bat is

5.A train is moving with people inside it. The train is moving very fast but the people inside are seated and not moving. Do they have Potential energy if the train is moving but every single person in the train is seated on the seats which are at a height from the ground?

• Yes
• No