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 categorized based on whether kinetic energy is conserved or lost.
Step 2: Key Formula or Approach:
Recall the theoretical definitions related to collisions:
By definition, momentum is conserved in all isolated collisions (elastic and inelastic).
Kinetic energy is conserved only in perfectly elastic collisions.
Step 3: Detailed Explanation:
In an elastic collision between two bodies, there is no net loss in kinetic energy in the system as a result of the collision. Therefore, both the total momentum and the total kinetic energy remain constant before and after the collision.
In contrast, an inelastic collision conserves momentum but results in a loss of macroscopic kinetic energy (which turns into heat, sound, or deformation energy).
Step 4: Final Answer:
Both momentum and kinetic energy are conserved.