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KCET2009PhysicsRotational Motion

A door 1.6 ~m wide requires a force of 1 ~N to be applied at the free end to open or close it. The force that is required at a point 0.4 ~m distance from the hinges for opening or closing the door is

Options

  1. A1.2 ~N
  2. B3.6 ~N
  3. C2.4 ~N
  4. D4 ~N

Correct answer

D. 4 ~N

Step-by-step solution

Here, torque =1.6 1=1.6 ~N - m So, when d=0.4 ~m , F = d = 1.6 0.4 =4 ~N

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