I don't really know the answer but maybe north pole and south pole?
Answer:
The total momentum of the system before the collision is 0.0325 kg-m/s due east direction.
Explanation:
Given that,
Mass of the cart, m = 250 g = 0.25 kg
Initial velocity of the cart, u = 0.31 m/s (due right)
Mass of another cart, m' = 500 g = 0.5 kg
Initial velocity of the another cart u' = -0.22 m/s (due left)
Let p is the total momentum of the system before the collision. It is given by :

So, the total momentum of the system before the collision is 0.0325 kg-m/s due east direction.
No it won't. It'll vary inversely as the square of the separation.