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 of rotation for a duration of ......... \(\sec\).

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Correct Answer

(A) \(2\)

Step-by-step Solution

Detailed explanation

\(KE = \frac{1}{2}I{\omega ^2} = 1200\left( {given} \right)\)

\( \Rightarrow \omega = 40\,rad/s\)

\(\,\,\,\,\,\,\,\omega = {\omega _0} + \alpha t\)

\(\,\,\,\,\,\,\,40 = 0 + \left( {20} \right)\,t\)

\( \Rightarrow t = 2\,\sec .\)

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