Question

Find the total torque acting on the body shown in the figure about the point $O$

• A. $2Fr\text{N-m}$
• B. $Fr\text{N-m}$
• C. $0\text{N-m}$
• D. $\frac{Fr}{2}\text{N-m}$

Answer 1

The correct option is C $0\text{N-m}$


From figure, we get
Torque about point $O$ ${\tau }_{net}={\tau }_1+{\tau }_2+{\tau }_3+{\tau }_4=-F.r+F.r\sin {30}^{\circ }+0+F\sin {30}^{\circ }.r$
(Taking anticlockwise torque to be positive.)
$\Rightarrow {\tau }_{net}=0$