A train engine is pulling four boxcars, each of inertia m. The engine can exert a force of magnitude F on what it is pulling.Part AAssuming that friction can be ignored, what is the tension in the coupler between the engine and the first car as the train starts off?Express your answer in terms of some or all of the variables m and F.Part BWhat is the tension in the coupler between the first car and the second car as the train starts off?Express your answer in terms of some or all of the variables m and F.Part CWhat is the tension in the coupler between the second car and the third car as the train starts off?Express your answer in terms of some or all of the variables m and F.Part DWhat is the tension in the coupler between the third car and the fourth car as the train starts off?Express your answer in terms of some or all of the variables m and F.