An empty, free-moving box car with a mass of 22,509 kg is coasting along at 4.21 m/s, when it runs into a second, stationary loaded box car with a mass of 31,647 kg. what is the speed of the two cars after they collide and attach?

Final velocity, v = 1.74 m/s

Explanation:

Given that,

Mass of car 1, m₁ = 22509 kg

Velocity of car 1, v₁ = 4.21 m/s

Mass of car 2, m₂ = 31647 kg

It is stationary, v₂ = 0

Let v be the velocity of the two cars after they collide and attach. It can be calculated using law of conservation of momentum as :

v = 1.74 m/s

So, the velocity of two cars after the collision is 1.74 m/s. Hence, this is the required solution.