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Question 30477
JEE Physics · Hard

Work, Power and Energy: Advanced — Rocket Propulsion MCQ

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Advanced — Rocket PropulsionHardQuestion 30477

Question

A rocket of initial mass M ejects gas at relative velocity u. When mass reduces to M/2, thrust force on rocket is equal to:
  1. A
    Mu/2
  2. B
    F = u(dM/dt)
    Correct
  3. C
    Mu(dM/dt)
  4. D
    u×M/2

Correct answer

F = u(dM/dt)

Explanation

Thrust = −u(dM/dt). Here dM/dt is the rate of mass ejection (negative since mass decreases). Thrust magnitude = u|dM/dt|, independent of current mass.

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