1) A 2,000-kilogram railroad car moving at 5 m/sec to the east collides with a 6,000-kilogram railroad car moving at 3 m/sec to the west. If the cars couple together, what is their velocity after the collision ? a ) Given ? b) Draw the situation given in the question with mass and velocity including arrows . c) Decide whether the collision is elastic or inelastic. The situation given in the problem is ( elastic , inelastic ) d) write an equation for this situation . e ) Solve for the unknown variable