1 - at restWell, as with (almost) all physical objects, it obeys all 3 laws, it primarily depicts the conservation of momentum. Whilst it does demonstrate the other 2, it is a particularly poor demonstration of the 2nd
2 - when balls from one end hit, the balls at the other end move the same distance as what the balls were released from
3 - the same number of balls move from the one end as the number of balls that were released
I may have mixed 2 and 3 up, it's been a while since I was laying DPCs