Answer:
Total momentum of the system before the collision is 60 kg-m/s.
Step-by-step explanation:
Given that,
Mass of Matt, m = 80 kg
Mass of Trey, m' = 90 kg
Initial speed of the Matt before the collision, u = 3 m/s (east)
Initial speed of the Trey before the collision, u = -2 m/s (west)
After the collision, Matt is moving 1.5 m/s to the west.
We need to find the total momentum of the system before the collision. We know that the momentum is given by the product of mass and velocity. Initial momentum is given by :

So, the total momentum of the system before the collision is 60 kg-m/s. Hence, this is the required solution.