A constant torque acting on a uniform circular wheel changes its angluar momentum from `A_0` to `4 A_0` in `4 s`. The magnitude of this torque is equal to.

Options

A. `3 A_0//4`
B. `4 A_0`
C. `A_0`
D. `12 A_0`

Answer

A

Explanation

(a) `tau = (Delta L)/(Delta t) = (4 A_0 - A_0)/(4) = (3 A_0)/(4)`