A ring starts from rest and acquires an angular speed of `10 rads^-1` in `2 s`. The mass of the ring is `500 gm` and its radius is `20 cm`. The torque on the ring is.

Options

A. 0.02 Nm
B. 0.20 Nm
C. 0.10 Nm
D. 0.01 Nm

Answer

C

Explanation

( c) `prop = (omega)/(t) = (10)/(2) = 5 rad//s^2`
`tau = I prop = MR^2 prop = 0.500 xx (0.20)^2 xx 5 = 0.10 Nm`.