A) \[8\hat{i}-10\hat{j}-8\hat{k}\]
B) \[8\hat{i}+10\hat{j}+12\hat{k}\]
C) \[10\hat{i}-10\hat{j}-\hat{k}\]
D) \[8\hat{i}+10\hat{j}-12\hat{k}\]
Correct Answer: B
Solution :
: Here, \[\overrightarrow{r}=\hat{i}-2\hat{j}+\hat{k}\] \[\overrightarrow{F}=5\hat{i}+2\hat{j}-5\hat{k}\] Torque, \[\overrightarrow{\tau }=\overrightarrow{r}\times \overrightarrow{F}\] \[=\left| \begin{matrix} {\hat{i}} & {\hat{j}} & {\hat{k}} \\ 1 & -2 & 1 \\ 5 & 2 & -5 \\ \end{matrix} \right|\] \[=\hat{i}(10-2)-\hat{j}(-5-5)+\hat{k}(2-(-10))\] \[=8\hat{i}+10\hat{j}+12\hat{k}\]
You need to login to perform this action.
You will be redirected in
3 sec
