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Question 30575
JEE Physics · Hard

Center of Mass, Momentum and Collision: Advanced — Mass Varying System MCQ

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Advanced — Mass Varying SystemHardQuestion 30575

Question

Sand falls at rate dm/dt = μ kg/s onto a moving conveyor belt (speed v). Force needed to keep belt at constant speed is:
  1. A
    μv
    Correct
  2. B
    μv²
  3. C
    μg
  4. D
    gμ/v

Correct answer

μv

Explanation

The conveyor must accelerate each new piece of sand from 0 to v. By Newton's second law: F = d(mv)/dt = v(dm/dt) = μv.

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