Q. Find the torque about the origin when a force of $3\hat{j}$ N acts on a particle whose position vector is $2\hat{k}$ m.
A) $6\hat{j}$ N m
B) $-6\hat{i}$ N m
C) $6\hat{k}$ N m
D) $6\hat{i}$ N m
Explanation
[Solution] $\vec{\tau} = \vec{r} \times \vec{F} = 2\hat{k} \times 3\hat{j} = -6\hat{i}$ N m. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.