Correct Answer - Option 2 : 1
CONCEPT:
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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.
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Coefficient of restitution: It is the ratio of the final relative velocity between two objects after they collide to the initial relative velocity between two objects before they collide.
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Newton's law of restitution: Mathematically, it says
v2 − v1= − e (u2 − u1)
where u1 is the initial velocity of the first ball, u2 is the initial velocity of the second ball, v1 is the final velocity of the first ball, v2 is the final velocity of the second ball, and e is the coefficient of restitution.
The coefficient of restitution always lies between 0 ≤ e ≤ 1.
- When e = 1, the collision is elastic.
- When e = 0, the balls remain in contact after the collision. (perfect inelastic collision)
EXPLANATION:
- For a perfectly elastic collision, the relative velocity between two objects after they collide and the initial relative velocity between two objects before they collide are equal.
So e = 1
- So the correct answer is option 2.
