Have you considered thinking about what motivation actually is, what it means? Firstly you might ask yourself what motivates you?
You can actually take some of the examples above, those people would be motivated by the threat of physical pain, but it could also be any other kind of pain or suffering, e.g. financial, that they would want to avoid. A more positive way of motivating people would be the possibility of some kind of reward, a bonus for instance.
Remind you of an old cliché you might have heard of? (clue - it has carrot and stick in it.)