Question

Find work done in moving a particle along vector S= (4i -j+7k)m,if applied force F= (i +2j-k) N

Answer 1

work done = F×S
then
W= (4i-j+7k ) ×(I+2j-k)
W= 4×1-1×2-7×1
W= 4-2-7
W= 4+9
W= 13