Question
A triangular plate is shown. A force $\overrightarrow{ F }=4 \hat{ i }-3 \hat{ j }$ is applied at point $P$. The torque at point $P$ with respect to point $'O'$ and $'Q'$ are
✓
Answer
$\overrightarrow{ F }=4 \hat{ i }-3 \hat{ j }$
$\overrightarrow{ r }_{1}=5 \hat{ i }+5 \sqrt{3} \hat{ j } \& \overrightarrow{ r }_{2}=-5 \hat{ i }+5 \sqrt{3} \hat{j}$
Torque about $'O'$
$\vec{\tau}_{0}=\overrightarrow{ r }_{1} \times \overrightarrow{ F }=(-15-20 \sqrt{3}) \hat{ k }=(15+20 \sqrt{3})(-\hat{ k })$
Torque about $'Q'$
$\vec{\tau}_{Q}=\overrightarrow{ r }_{2} \times \overrightarrow{ F }=(-15+20 \sqrt{3}) \hat{ k }=(15-20 \sqrt{3})(-\hat{ k })$
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