How is an internal combustion engine powered?

Answer 1

By the heat generated when fuel and air are mixed and then ignited. (set fire to)

Inside an internal combustion engine there are pistons that go up and down (like your legs on a bike) they are inside cylinders and look and work much like a syringe. The ends of the pistons are connected to a "crank shaft" and spins round and round (just like the bike)

As the piston comes down, air and fuel are sucked into the engine through the "inlet valve" and when the piston gets to the bottom, the inlet valve closes, then the piston is forced upwards, compressing the air and fuel. Then once the piston reaches the top, it is ignited, and the fire that burns, heats up the air so much, it expands rapidly, and forces the piston down, putting force into the crank shaft and pushing the car (or whatever) along. Then when the piston gets to the bottom, the exhaust valve opens, and the piston rises again and blows the burnt gas out the exhaust system. Then the inlet valve opens again, and the whole cycle continues.

This process typically happens between 5 to 35 times a second inside the average car engine.