(Solved): 19. A speeding train engine of mass 12,000kg collides with a stationary train car of mass 6,000 ...

19. A speeding train engine of mass $12,000\mathrm{kg}$ collides with a stationary train car of mass $6,000\mathrm{kg}$. After the collision, the crashed train cars slide together for a distance of $470\mathrm{m}$ before coning to rest. By measuring the coefficient of friction, you determine that the wreckage experienced a friction force of $18,000\mathrm{N}$ as it came to rest. Use this forensic information to determine the initial velocity of the speeding train engine.