Q 11-03-023NEETJEE MainEasy
A force $\vec{F} = (2\hat{i} + 3\hat{j} - \hat{k})$ N moves a particle from the point $(1, 2, 0)$ m to the point $(4, -1, 3)$ m. The work done by the force is
Answer: (D) $-6$ J
$$\vec{s} = (4 - 1)\hat{i} + (-1 - 2)\hat{j} + (3 - 0)\hat{k} = 3\hat{i} - 3\hat{j} + 3\hat{k}$$
$$W = \vec{F}\cdot\vec{s} = 6 - 9 - 3 = -6\ \text{J}$$
Solution by Sreeraj P, M.Sc Physics