Give the expression for work done if angle between force `vecF` and displacement `vecs` is `theta`. Also find the dimensions and SI unit of work.

Explanation

Let us consider a force `(vecF)`, acting on a body that moves it by a displacement in some direction `(dvecr)` as shown in the figure.
Work done (W) by the force on the body is
`W=vecF.dvecr" "….(1)`
Here, the product `vecF.dvecr` is a scalar product (or dot product). The scalar product of two vectors is a scalar. Thus, work done is a scalar quantity. The SI unit of work done is Nm (or) joule (J). Its dimensional formula is `[ML^(2)T^(-2)]`
The equation (1) is,
`W=Fdr cos theta`