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A book of weight 20 N is pressed between two hands and each hand exerts a force of 40 N . If the book just starts to slide down. What is the value of the coefficient of friction?

Correct answer

0.25

Step-by-step solution

Block is in horizontal equilibrium. In the vertical direction, it is in limiting equilibrium. μ s = F s R = m g R = 20 40 = 0.5 m g = 2 f r 1 = 2 μ F μ = m g 2 F = 20 2 × 40 = 0 . 25

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