Answer:
Option A: 600 kg.m/s westward
Explanation:
The scenario in question here implies a Linear (straight horizontal line) collision.
Usually, when there is a collision between two(2) objects moving opposite to each other like stated above, the object with the higher momentum tends to be more difficult to stop.
The Formula to use here is: P(w) + P(e) = P(total)
where P(w) is the momentum of the first vehicle travelling Westward,
P(e) is the momentum of the second vehicle travelling Eastward and
P(total) is the total amount of momentum after the collision.
Therefore,
1,800 kg.m/s + (-1,200 kg.m/s) = 600 kg.m/s in the westward direction (Our Answer)
Please note that the negative sign in front of (-1,200 kg.m/s) implies that it is moving in a direction opposite to that of the other vehicle.