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NEETPhysicsMotion in Two Dimensions

A flywheel of moment of inertia 50 kg m ^2 starts from rest. If it attains an angular velocity of 20 rad/s in 4 s , the constant torque applied to it is

Options

  1. A1000 N m
  2. B250 N m
  3. C10 N m
  4. D4000 N m

Correct answer

B. 250 N m

Step-by-step solution

Given, initial angular velocity _i = 0 Final angular velocity _f = 20 rad/s Time t = 4 s Using the first equation of rotational kinematics: _f = _i + t 20 = 0 + (4) = 5 rad/s ^2 The required constant torque is given by: = I = 50 5 = 250 N m Answer: 250 N m

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