A disc of moment of inertia `3 kg m^(2)` is acted upon by a constant torque of 60 Nm, if the disc is at rest, then the time after which the angular velocity of the disc is 90 rad/s, will be

Options

A. 1.5 s
B. 3 s
C. 4.5 s
D. 6 s

Answer

C

Explanation

`tau = I alpha =(I(omega_(2)-omega_(1)))/(t)`