Question

A force $10\widehat{-k}N$ acts on the origin of the coordinate system. Find the torque about the point $(1m,-1m,0m).$

Answer 1

Given,

Force, $F=10(-\hat{k})N$

$\overrightarrow{r}=\hat{i}-\hat{j}$

Torque,

$\tau =\overrightarrow{r}\times \overrightarrow{F}$

$\tau =(\hat{i}-\hat{j})\times (-10\hat{k})$

$\tau =10\hat{i}-10\hat{j}$