Can a normal force do work?
Note: work = $Fd\cos(\theta)$, where $F$ is the magnitude of the force, $d$ is the magnitude of the displacement, and $\theta$ is the angle between the two.
Attempt at an answer:
My textbook's answer:
No the normal force does not cause an object to be displaced, it's perpendicular to the direction of motion.
But what if the displacement is in a vertical direction, so now the normal force with is at either 0 degrees or 180 degrees? For example, in an elevator if it is accelerating upwards doesn't the normal force do work? Or for example, when someone jumps up he pushes down on the ground, then by Newton's third law the ground pushes back up, so that's a normal force that causes him to be displaced.
Which answer is correct and if my examples are wrong what is wrong in them?