Question:
Calculate the total torque acting on the body shown in figure about the point $O$.
Solution:
Torque $=F \times d_{\perp}$
Consider anticlockwise torque as negative and clockwise torque as positive.
$\tau_{N}=\tau_{10}+\tau_{15}+\tau_{5}+\tau_{20}$
$=(10)(4)-(15)\left(6^{\sin 37}\right)+5(0)-20\left(4^{\cos 60^{\circ}}\right)$
$\tau_{\text {Net }}=-0.54$
$\mathrm{T}=0.54 \mathrm{~N}-\mathrm{m}$ (anticlockwise direction)