When a cat goes up stairs, it will pull itself up with front legs and push with back ones. This cat is bouncing slightly(lowering itself) to let gravity do the work, obviously going down the stairs.
actually it is somewhat wrong. they are not simultanious.
the particle alternates in position randomly. however when observed, (that means you are putting a small amount of force into it so you can see it) the force makes its movements definite and predictable. take that experiment with the firing of electrons through metal slits for example...