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AP EAMCET2010PhysicsRotational Motion

A fly-wheel of mass 25 ~kg has a radius of 0.2 ~m . It is making 240 rpm . What is the torque necessary to bring to rest in 20 ~s ?

Options

  1. A2 Nm
  2. B0.4 Nm
  3. C2 Nm
  4. D4 Nm

Correct answer

B. 0.4 Nm

Step-by-step solution

= 2 n t = 2 240 60 20 = 2 4 20 = 2 5 Torque, =I =M R^2 =25 (0.04) 2 5 =0.4 Nm

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