Branch of science concerned with the nature of heat and its transformations to mechanical energy. Energy can neither be created nor be destroyed. It can change form and travel to other places, but it can always be accounted for. However, the energy output of the train cannot exceed the energy input. It flows from hot to cold.
Disorder tends to increase.
Entropy tends to increase. Force x Distance. Mass x Gravity x Distance. You can use this equation to calculate work done when you apply a force to an object and move it a certain distance. Work is measured in newton-meters or Joules.