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Question 30463
JEE Physics · Hard

Work, Power and Energy: JEE — Elastic Head-on MCQ

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JEE — Elastic Head-onHardQuestion 30463

Question

Mass m₁ = m moving at v₀ collides elastically with m₂ = 3m at rest. Speed of m after collision:
  1. A
    v₀/2
  2. B
    v₀/4
  3. C
    −v₀/2
    Correct
  4. D
    v₀/3

Correct answer

−v₀/2

Explanation

For elastic collision: v₁' = (m₁−m₂)v₀/(m₁+m₂) = (m−3m)v₀/(4m) = −v₀/2. Negative = reverses direction.

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