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Question 30529
JEE Physics · Hard

Center of Mass, Momentum and Collision: COM — Moved by Internal Forces MCQ

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COM — Moved by Internal ForcesHardQuestion 30529

Question

Two boys (equal mass) on a frictionless trolley throw a ball between them. The trolley's centre of mass:
  1. A
    Moves forward
  2. B
    Moves backward
  3. C
    Remains stationary
    Correct
  4. D
    Oscillates

Correct answer

Remains stationary

Explanation

With no external horizontal force, the COM of the entire system (boys+trolley+ball) remains stationary. The trolley moves but the COM of the system does not.

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