A locomotive is pulling an empty freight car with a constant acceleration on a horizontal surface. The mass of the locomotive is five times the mass of the car. Which statement is true about the force applied by the car on the locomotive?

Question

A locomotive is pulling an empty freight car with a constant acceleration on a horizontal surface. The mass of the locomotive is five times the mass of the car. Which statement is true about the force applied by the car on the locomotive?
A. 5x greater than the force of the locomotive on the car
B. 5x less than the force of the locomotive on the car
C. Zero since they move with a constant acceleration
D. Equal to the force of the locomotive on the car
E. More info is required

I think the answer is D, but I'm a little confused.

R_scott · Answer

you're correct Newton's equal and opposite reactive force