Question

Find the work done if a force <2,1,1> moves an object from the terminal point of V <-1,2,3> to the terminal point of <0,4,-2>

Answer 1

Using vectors, work is defined by \[W=F \cdot d\] where F is your force vector and d is your distance vector. Thus, since \[F=\left<2,1,1 \right>\] and your distance vector d is \[d= \left< 0-(-1), 4-2,-2-3\right>=\left< 1,2,-5\right>\] then work is \[W=2(1)+1(2)+1(-5)=-1\]