posted by jose2 .
A short train (an engine plus four cars) is accelerating at 1.10 . The mass of each car is 38000 , 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.
a.What is the force of the engine on the first car?
b.What is the force of the first car on the second car?
c.What is the force of the second car on the third car?
d. And what is the force of the third car on the fourth car?
We will be happy to critique your thinking. Wouldn't it be wonderful if trains could have negligible friction.
A. The engine is pulling all four cars at the specified acceleration. Then
Force = 4 x 38,000 x 1.10 = 167 200 N
B. Now the first car is pulling the other three cars.
Force = 3 x 38,000 x 1.10 = 125 400 N
And similarly C. Force = 2 x 38,000 x 1.10 = 83 600 N; D. 41 800 N