A short train (an engine plus four cars) is accelerating at 1.40 m/s^2 . The mass of each car is 3.70×104 kg, and each car has negligible frictional forces acting on it. In solving this problem, note the importance of selecting the correct set of cars to isolate as your object
1) What is the force of the engine on the first car?
2) What is the force of the first car on the second car?
3) What is the force of the second car on the third car?
4) And what is the force of the third car on the fourth car?