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 s
B. 2 s
C. 8 s
D. 10 s

Answer

B

Explanation

(b) `KE = (1)/(2) I omega^2 rArr KE = (1)/(2) I omega^2`
`rArr omega = 50 rad//s t= (omega)/(prop) = (50)/(25) = 2 s`.