Question

Calculate the total torque acting on the body shown in figure (10-E2) about the point O.

Answer 1

Torque about a point = Total force $\times$ perpendicular distance

From the point to that force

Let anticlockwise torque = +ve

and clockwise acting torque = -ve

Force acting at the point B is 15 N

Therefore,

Torque at O due to this force

$=15\times 6\times {10}^{-2}\times sin{37}^{\circ }$

$=15\times 6\times {10}^{-2}\times \frac{3}{5}$

$=0.54N-m\text{(anticlockwise)}$

Force acting at the point c is 10 N.

Therefore,

Torque at O due to this force

=$10\times 4\times {10}^{-2}$ = 0.4 N-m (clockwise)

Force acting at the point A is 20 N.

Therefore, Torque due to this force

$=20\times 4\times {10}^{-2}\times sin{30}^{\circ }$

$=20\times 4\times {10}^{-2}\times \frac{1}{2}$

$=0.4\text{N-m(Anticlockwise)}$

Therefore,

Resultant torque acting at O`

= (0.54-0.4+0.4)

= 0.54 N-m