A small toy car with a mass of 0.4 kg and a velocity of 5 m/s crashes into another toy car that was at rest with the same mass. The first toy car stops moving and the second toy car then moves forward and crashes into the third toy car that was at rest with a mass of 0.2 kg.
a) If the system is closed, what is the velocity of the third toy car?
b) Show how you calculated the velocity in the space below.