I'm busy writing a train simulator. I need to calculate the fuel consumption of the locomotive. I know that Work = Force x distance. From that, I can easily use energy density and work out how many kg of fuel was used.
I have a total resistance force (Fres) for the train (gradient, aerodynamic resistance, rolling resistance).
I also have the force produced by the locomotive (Floc).
I can easily calculate the train's acceleration by knowing Facc, where Facc = Floc - Fres.
The question is this: in order to calculate the fuel used by the locomotive, do I use Facc or Floc?
I feel that the locomotive needs to use energy (its fuel) to overcome resistance. But Wikipedia (https://en.wikipedia.org/wiki/Work_(physics)) says that work is only done by the resultant force. This would mean that at terminal speed, the locomotive would consume no fuel, the forces are balanced, and there is no change in EK (Kinetic energy). Clearly, this sounds wrong.