A particle moves from a point \(-2\hat{i} + 5\hat{j}\) to \(4\hat{j} + 3\hat{k}\) when a force of \(4\hat{i} + 3\hat{j}\) is applied. How much work has been done by the force?
Answer & explanation
Correct answer: option 3
Displacement : \(\vec{S} = \vec{r_2} - \vec{r_1} \)
\(\vec{r_1}\) = \(-2\hat{i} + 5\hat{j}\) ; \(\vec{r_2}\) = \(4\hat{j} + 3\hat{k}\)
⇒ \(\vec{S} = 2\hat{i} - \hat{j} + 3\hat{k}\)
\(\vec{F} = 4\hat{i} + 3\hat{j}\)
⇒ W = \(\vec{F}.\vec{S}\)
W = 5 J