A body is subjected to a constant force given by
`vecF(N)=-hati+2hatj+3hatk`
What is the work done by this force in moving the body through a distance of 4 m along the z=axis and then 3 m along the y-axis?

Explanation

The formula to be used is `W=vecF.vecS`
For first part of the displacement, we have
`vecS(m)=4vecK`
So, work done is given as
`W=vecF.vecS`
`=(-hati+2hatj+3hatk).(4hatk)`
`=12Nm=12J`
For second part of the displacement, we have
`vecS(m)=3hatj`
So, work done is given as
`W=vecF.vecS`
`=(-hati+2hatj+3hatk).(3hatj)`
`=6N-m=6J`
Total work done is thus given by `W=12+6=18J`