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A door 1 . 6 m wide requires a minimum force of 1 N to be applied at the free end to open or close it. The minimum force that is required at a point 0 . 4 m away from the hinges for opening or closing the door is

Options

  1. A1 . 2 N
  2. B2 . 4   N
  3. C3 . 6   N
  4. D4 N

Correct answer

D. 4 N

Step-by-step solution

It is given in the question, torque τ = 1.6 × 1 = 1.6 N m So, when d = 0 .4 m , F = τ d = 1.6 0.4 = 4 N .

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