Question

In an elastic collision, the kinetic energy of the system ______.
1. decreases
2. increases
3. remains constant.
4. first decreases then increases

Answer 1

Correct Answer - Option 3 : remains constant.

CONCEPT:

• Collision: An event in which two or more bodies exert forces on each other for a very short time is called a collision.
  • It results in the exchange or transformation of energy.
• Elastic Collision: A collision that takes place between two objects in which no energy is lost.
• In the case of elastic collision, the kinetic energy and momentum both are conserved.

EXPLANATION:

• In the elastic collision, both momentum and kinetic energy are conserved.
• Since in the elastic collision kinetic energy of the system is conserved, it will remain constant.
• So the correct answer is option 3.

Characteristic of elastic and inelastic collision:

Elastic collision	Inelastic collision
The kinetic energy is conserved.	The kinetic energy is not conserved.
The momentum is conserved.	The momentum is conserved.
The total energy is conserved.	The total energy is conserved.
Forces involved during a collision are conservative.	Some or all of the forces involved during a collision are non-conservative.