Q. A point of application of a force $\overrightarrow{F} = 5\widehat{i} - 4\widehat{j} + 2\widehat{k}$ is moved from $\overrightarrow{r_{1}} = 2\widehat{i} + 7\widehat{j} + 4\widehat{k}$ to $\overrightarrow{r_{2}} = 5\widehat{i} + 2\widehat{j} + 3\widehat{k}$ the work done is
A) 22 units
B) $- 22$ units
C) 33 units
D) $-$33 units
Explanation
(a) Displacement , $\overrightarrow{r_{\ }} = ({\overrightarrow{r_{\ }}}_{2} - {\overrightarrow{r_{\ }}}_{1})$ and workdone $= \overrightarrow{F}.\overrightarrow{r_{\ }}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.