A body constrained to move along the z-axis of a coordinate system is subject to a constant force F given by

F =\( -\hat{i}+2\hat{j}+3\hat{k}F\;N\)

where i, j, k, are unit vectors along the x- y- and z-axis of the system respectively. What is the work done by this force in moving the body at a distance of 4 m along the z-axis?

Asked by Abhisek | 1 year ago | 146

The body is displaced by 4 m along z-axis

\( \vec{S} =0\hat{i}+0\hat{j}+4\hat{k}S\)

\( \vec{F} =-\hat{i}+2\hat{j}+3\hat{k}F\)

Work done,

W =\( \vec{F}.\vec{S} = (0\hat{i}+0\hat{j}+4\hat{k})(-\hat{i}+2\hat{j}+3\hat{k})\)

= 12\( (\hat{k}.\hat{k})\) Joule = 12 Joule

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