How do cars move, it seems inexplicable (to me)?

Question

Confiteor, I have only a rudimentary knowledge of how machines work. I'll be discussing fossil fuel engines only.

First off, I have a block of iron, B. I find a pan balance. I place B in one of the pans. I then place X in the other pan. X > B. The arms will move in such a way that you can infer, B can't lift X. Now remove X, place Y in its place. Y = B. Equilibrium!!!

Conclusion: If X > B then B can't lift X (we're talking about weight here).

My question is, with a car, the weight of the fuel (even at full tank) is much, much, less than the weight of the car + fuel. and yet ... a fraction of the fuel "lifts" the car.

Quomodo?

Answer 1

the gasoline contains a tremendous amount of stored chemical energy per pound of weight. the engine in the car burns the gasoline to release the stored chemical energy as heat and convert that into shaft work, which turns the wheels of the car.