Question

How do you find done in moving a particle P (1, 3) to Q(-3, 5) if the magnitude and direction of the force is given by `v=-2i+3j`?

Answer 1

`WD=14J`

Explanation:

Word done `=vecF.vecs`

displacement in this case is given by `vec(PQ)`

`vec(PQ)=vecq-vecp= ((-3),(5))-((1),(3))=((-4),(2))`

`WD=vecF.vec(PQ)=((-2),(3)).((-4),(2))=(-4)xx(-2)+3xx2`

`WD=8+6=14J`