Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Work Power Energy

Question:

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?

Options:

8 J

11 J

5 J

 2 J

Correct Answer:

5 J

Explanation:

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