Question

How do you find done in moving a particle P (0,0) to Q(4,7) if the magnitude and direction of the force is given by `v=<1,4>`?

Answer 1

`32" unit"`.

Explanation:

Suppose that, under the influence of a force `vecF,` a particle

moves from point `P` to point `Q`.

Then, the work `W` done is given by, `W=vecF*vec(PQ)`.

We have, `vecF=(1,4)` and for the displacement `vec(PQ)`,

`vec(PQ)=Q(4,7)-P(0,0)=(4,7)`.

`:. W=(1,4)*(4,7)=(1)(4)+(4)(7)=4+28=32" unit"`.