Answer:
18.75 m/s EAST
Step-by-step explanation:
This is a conservation of momentum problem. Total momentum before the collision must equal total momentum after the collision.
Momentum = P = mv
Assume positive direction is to the EAST, negative is to the WEST
v = velocity of car+truck stuck together after the collision
(3000 kg)(25 m/s) + (1000 kg)(0 m/s) = (3000 kg + 1000 kg)(v)
75,000 kg·m/s = (4,000 kg)(v)
v = (75,000 kg·m/s) / (4,000 kg) = 18.75 m/s EAST