Question

A force of 3i+2j+4k N gives displacement of 10j m.the work done is?

A. 20J

B. 26J

C. 32J

D. Zero

Answer 1

The work done

$$W=\vec F\cdot \vec d$$

$$W=(3\hat i+2\hat j+4\hat k)\cdot (10\hat j)\\ =20\:\rm J$$