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Moment of inertia of a body about a given axis is 1.5 kg m 2 . Initially the body is at rest. In order to produce a rotational kinetic energy of 1200 J, the angular acceleration of 20 rad/s 2 must be applied about the axis for a duration of :

1. 5 s
2. 3 s
3. 2.5 s
4. 2 s

Correct answer: 2 s

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