A locomotive with two carriages drives out of the station. The locomotive has a mass of 3.0 tonnes, and each of the two wagons has a mass of 2.0 tonnes. The force that accelerates the locomotive is 17.5 kN. We assume that there is no friction. a) Calculate the acceleration of the train
b) Draw the forces acting on the middle carriage as the train accelerates
c) Calculate the magnitude of the forces acting on the middle carriage during acceleration
d) What is the speed of the train when it has traveled 80 m?

Your answer is 120miles 

Since you have not included the experiment situation and the data, of course, i can not give you specific details about it. but i can you with this question.1) i will assume that the motion is projectile (parabolic) motion.2) yes, the horizontal distance depends on the horizontal velocity as, naming vx the horizontal velocity and t the time, it is: x = vx × t3) now, observe that the flight time depends on the vertical velocity as, naming voy the initial vertical velocity, t the time and y the vertical distance before reaching the ground: y = yo + voy×t - gt² / 2.the higher the initial vertical velocity (voy) the longer the object will be flying and so t will be higher in the equation for the horizontal distance.that explains the relationship between the horizontal distance and the horizontal velocity.