A body is constrained to move along the z-axis is subject to a constant force F =`(-hati+2hatj+3hatk) N`. Calculate the work done by this force in moving the body a distance of 4m along the z-axis .

Explanation

Displacement , `vecs =4hatk m `
Force, `vecF=(-hati+2hatj+3hatk)N`
`therefore` Work done , W`=vecF*vecs=(-hati+2hatj+3hatk)*4hatk`
`=-4hati*hatk+8hatj*hatk+12hatk*hatk`
=0+0+12`*`1= 12 J.