Question

The point of application of a force
F = (6j+8k) is displaced from A(1,-1,2) to B(-1,1,2).
Then the work done is​

Answer 1

Explanation:

the displacement vector dr=( -i+j+2k)-(i-j+2k)

dr= -i+j+2k-i+j-2k

dr= -2i+2j

the work done w =F.dr

w= (6j+8k).(-2i+2j)

w=12 unit.

where we have used displacement vector = final position vector- initial position vector

and i.j = j.k =k.i =0