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Question 30541
JEE Physics · Hard

Center of Mass, Momentum and Collision: Rocket — Velocity MCQ

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Rocket — VelocityHardQuestion 30541

Question

A rocket starts from rest and ejects gas at u = 2 km/s relative to rocket. When its mass reduces to e⁻¹ of its initial mass M₀, speed of rocket is:
  1. A
    2 km/s
    Correct
  2. B
    2/e km/s
  3. C
    2e km/s
  4. D
    u/e km/s

Correct answer

2 km/s

Explanation

Tsiolkovsky equation: v = u × ln(M₀/M) = 2 × ln(e) = 2 × 1 = 2 km/s.

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