Question

In an elastic collision,

• A. both momentum and kinetic energy are conserved
• B. only momentum is conserved
• C. only kinetic energy is conserved
• D. neither kinetic energy nor momentum is conserved
• E. forces involved are non-conservative forces

Hint:

Always remember: Momentum is conserved in EVERY collision. Kinetic energy is ONLY conserved in elastic collisions.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Collisions are classified based on the conservation of kinetic energy.
In all types of collisions (where no external net force acts), total linear momentum is always conserved.
In an elastic collision, there is no permanent deformation and no heat is generated, so the total kinetic energy before the collision equals the total kinetic energy after the collision.

Step 2: Detailed Explanation:
By definition:
1. Linear Momentum: Total momentum is always conserved in any collision (elastic or inelastic) because internal forces cancel out.
2. Kinetic Energy: Specifically in an elastic collision, kinetic energy is conserved. In inelastic collisions, some kinetic energy is converted into other forms (heat, sound, deformation energy).
Therefore, in an elastic collision, both are conserved.

Step 3: Final Answer:
In an elastic collision, both momentum and kinetic energy are conserved.