The moment of inertia of a body about a given axis is `1.2 kg m^(2)`. Initially, the body is at rest. In order to produce a rotational `KE` of `1500 j`, for how much duration, an acceleration of `25 rad s^(-2)` must be applied about that axis ?

Options

A. `4 sec`
B. `2 sec`
C. `8 sec`
D. `10 sec`

Answer

B

Explanation

`(1)/(2) xx 1.2 w^(2) = 1500`
`omega^(2) = (30000)/(1.2)`
`omega = 50`
`omega = "at" rArr t = 2 sec`.