Question

Force F=300 N acting vertically upward at x=2 m, y=2 m. The magnitude of moment of force about origin is

• A. 600 Nm
• B. 660 Nm
• C. 300 Nm
• D. 330 Nm

Answer 1

The correct option is A 600 Nm

$\begin{array}{c}\text{We have force vector}\overrightarrow{F}=300\hat{j}\\ \text{and radial vector of point}\overrightarrow{\mu }=2\hat{i}+2\hat{j}\\ \Rightarrow \text{Force moment}=\overrightarrow{r}\times \overrightarrow{F}\\ =(2\hat{i}+2\hat{j})\times \left(300\hat{j}\right)\\ =600\hat{k}\\ \text{Force moment}\overline{\tau }=600Nm\\ \text{Hence, option}\left(A\right)\text{is correct.}\end{array}$