A thin uniform rigid rod of mass `m` and length `l` is in mechanical equilibrium under the constraints of horizontal and vertical rough surfaces. Then select correct option(s):

Options

A. The net torque of normal reactions about `O` is equal to `mg"(l)/(2) cos theta`
B. The net torque of friction about `O` is zero
C. The net torque of normal reactions is numerically equal to net torque of frictional force about the `CM` of road.
D. none of these

Answer

A, B, C

Explanation

As. `overset(vec)(a_(cm)) = 0` , and `overset(vec)alpha = 0`
`rArr sumoverset(vec)(F_(ext)) = 0`
`rArr sumt_(ext)` about any point will be same. Which is equal to zero.