Question

A force F 5i+6j-4k acting on body produces displacement S= 6i+5k .workdone by force is

Answer 1

As we know that the work done by a body is dot product of force and displacement.

Thus, W = F.S

F = 5i+6j-4k

S = 6i+5k

W = (5i+6j-4k).(6i+0j+5k)

By dot product we have,

W=30+0-20

W= 10 j

Answer 2

As we have work done by body and displacement both are in vector form ,

Work done = force x displacementAs given in question, W=(5i+6j-4k)(6i+0i+5k)by multiplying, we get 30 + 0 -20                      =10unitsthis is the work done by force.