Question

Find the work done by a force fâ =1.8i^+2.2j^n as it acts on an object moving from the origin to the point râ =56i^+31j^m.

Answer 1

Take the dot product:

$W=\mathbf F\cdot\mathbf r=(1.8\,\mathbf i+2.2\,\mathbf j)\cdot(56\,\mathbf i+31\,\mathbf j)$
$W=169\,\text{Nm}$