A body moves from a position $\mathbf{r}_{\mathbf{1}}$= (2$\widehat{\mathbf{i}}$-3$\widehat{\mathbf{j}}$-4$\widehat{\mathbf{k}}$) m to a position, r2= (3$\widehat{i}$-43$\widehat{j}$-5$\widehat{k}$) m under the influence of a constant force F= (4$\widehat{\mathbf{i}} - 4\widehat{\mathbf{j}} + 5\widehat{\mathbf{k}}$) N. The work done by the force is

Question

Dr. Abubacker · Accepted Answer

(a) Given,$r_{1} = 2\widehat{i} - 3\widehat{j} - 4\widehat{k}$
And ${\ \ r}_{2} = 3\widehat{i} - 4\widehat{j} + 5\widehat{k}$
Now, $r_{2} - r_{1} = \widehat{i} - \widehat{j} + 9\widehat{k}$
And $F = 4\widehat{i} + \widehat{j} + 6\widehat{k}$
$	herefore\ \ \ \ \ \ \ \ \ $work done = F.r
$W = \left( 4\widehat{i} + \widehat{j} + 6\widehat{k} ight).(\widehat{i} - \widehat{j} + 9\widehat{k}$)
$\ \ \ \ \  = 4 - 1 + 54 = 57\ J$

Explanation

Reviewed by Dr. Abubacker

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