The cat in the box experiment was to show how things work in quantum mechanics. In quantum mechanics, you can't know the speed
and orientation of a sub-atomic particle at the same time, as working out one stops you from working out the other. This is one of the
truly random things in the universe (ie. you can work out, for example, which way a coin wlil land by using computers and an array of sensors, whereas you can not work out both of the particle's properties). The cat in the box experiment is just to show how this kind of thing works, however, it isn't truly random whether the cat will die or not, so that's why we know the answer to the question "is the cat dead?". With sub-atomic particles, if you've worked out the orientation, the speed is unknown and truly random, yet it still has speed (and yes, 0 m/s is still a speed), so the particle's speed is every value at the same time (same principle as the cat; it is dead and alive at the same time).
Oh and by the way, I'm 14