A) 23 units
B) 19 units
C) 18 units
D) 21 units
Correct Answer: A
Solution :
[a] Moment of force, \[m=\overset{\to }{\mathop{r}}\,\times \overset{\to }{\mathop{F}}\,\] \[m=\left| \begin{matrix} {\hat{i}} & {\hat{j}} & {\hat{k}} \\ 2 & -2 & -3 \\ 3 & 4 & -3 \\ \end{matrix} \right|\] \[=\hat{i}(6+12)-\hat{j}(-6+9)+\hat{k}(8+6)\] \[=18\hat{i}-3\hat{j}+14\hat{k}\] \[=\sqrt{{{(18)}^{2}}+{{(-3)}^{2}}+{{(14)}^{2}}}\] \[=\sqrt{529}=23\] units.
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