Question:

A train locomotive is putting two cars of the same mass behind it. Determine the ratio of the tension in the coupling between the locomotive and the first car(FT1) to that between the first car and the second car (FT2), for any nonzero acceleration of the train.

Work:

F=ma

Car 1:FN- M1G=m1*a

Car 2:FN- M2G=m2*a

2FN- M1G- M2G=m1*a+m2*a

Answer:a=(-g(m1+m2))/(m1+m2))

Is this correct?

Thank You