Six identical cars are towing identical trailers at constant, albeit different, speeds along level roads in the desert. The trailers carry different loads, so their masses vary. The circumstances of each vehicle are shown here. Using the letter identifiers, rank the difference between the magnitude of the force exerted by the car on the trailer and the magnitude of the force exerted by the trailer on the car for each situation from greatest to least. If any situations have the same difference, give them the same ranking. Explain your reasoning in forming your rankings.
(a) Trailer load = 1000 kg; vehicle speed = 20 m/s
(b) Trailer load = 2000 kg; vehicle speed = 20 m/s
(c) Trailer load = 4000 kg; vehicle speed = 40 m/s
(d) Trailer load = 4000 kg; vehicle speed = 10 m/s
(e) Trailer load = 2000 kg; vehicle speed = 10 m/s
(f) Trailer load = 1000 kg; vehicle speed = 10 m/s