A 8700-kgkg boxcar traveling at 14 m/sm/s strikes a second boxcar at rest. The two stick together and move off with a speed of 5.0 m/sm/s. What is the mass of thesecond car?

m₂ = 15660 kg

Explanation:

Given that,

Before collision,

Mass of box car 1, m₁ = 8700 kg

Speed of box car 1, u₁ = 14 m/s

Speed of box car 2, u₂ = 0 (at rest)

After collision,

The two stick together and move off with a speed of 5 m/s

Let m₂ is the mass of the second car. As cars stick together, it is a case of inelastic collision. Using the conservation of momentum as follows :

So, the mass of the second car is 15660 kg.