Question

A force does work on an object if a component of the force:a. is perpendicular to the displacement of the object b. is parallel to the displacement of the objectc. is crossing the line of axis d. both a and b are correct

Answer 1

As we know that total work done by a force is given by

$W = F.d$

$W = Fdcos\theta$

so it is product of force and displacement along same direction

as we can write it as

$W = (Fcos\theta)(d)$

so it must be the product of force and displacement in same directions so correct answer must be

b. is parallel to the displacement of the object