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Question 30280
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Laws of Motion and Friction: Advanced — Non-uniform Friction MCQ

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Advanced — Non-uniform FrictionHardQuestion 30280

Question

A long uniform rod (mass M, length L) lies on a rough floor (μ). It is pushed from one end. The friction is distributed along its length. What is the retarding friction force?
  1. A
    μMg
    Correct
  2. B
    μMg/2
  3. C
    μMg/L
  4. D
    2μMg

Correct answer

μMg

Explanation

Total normal force = Mg (uniform distribution). Total kinetic friction = μ × Mg regardless of how distributed, as long as the rod slides uniformly. So total friction = μMg.

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