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A coin of mass 10   g is placed over a book of length 50   cm . the coin is on the verge of sliding when one end of the book is lifted to 10   cm up. The coefficient of static friction between the book and the coin is

Options

  1. A1 . 0
  2. B0 . 4
  3. C0 . 3
  4. D0 . 2

Correct answer

D. 0 . 2

Step-by-step solution

The coin will not slide if m g sin ⁡ θ = μ R i e , m g sin ⁡ θ = μ m g cos ⁡ θ ( a s R = m g cos ⁡ θ ) i e , tan ⁡ θ = μ H e r e , tan ⁡ θ = 10 50 2 - 10 2 = 0.2 ∴ μ = 0.2

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