Problem

Work done by a force

\mathbf{F}

on a body is

W = \mathbf{F} \cdot \mathbf{s}

, where

\mathbf{s}

is the displacement of body. Given that under a force

\mathbf{F} = (2\hat{i} + 3\hat{j} + 4\hat{k}) \text{ N}

a body is displaced from position vector

\mathbf{r}_1 = (2\hat{i} + 3\hat{j} + \hat{k}) \text{ m}

to the position vector

\mathbf{r}_2 = (\hat{i} + \hat{j} + \hat{k}) \text{ m}

. Find the work done by this force.