The work done by a force is defined by `W= vec F cdot vec S cdot` It is found that the work done is zero, even if `vec F and vec s` are not equal to zero. From this we conclude that

Options

A. `vec F and vec S` are acting in the same direction
B. `vec F and vec S` are acting in the opposite direction
C. `vec F and vec s` are acting at right angles
D. `vec F and vec s` are acting at an angle of `60^(@)`

Answer

C

Explanation

`W = vec F cdot vec s = F cos theta =0" but "F ne 0, s ne 0,`
`therefore cos theta = 0^(@)" "therefore theta =90^(@)" or "vec F bot vec s`