question_answer

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 \[20\text{ }rad/{{s}^{2}}\] must be applied about the axis for a duration of :-                                                                           [JEE Main 9-4-2019 Afternoon]

A)   2 s                 

B)        5s

C)   2.5 s  

D)        3 s

Correct Answer: A

Solution :

[a] Given moment of inertia

Angular Acc.