An internal combustion engine converts what into mechanical energy?

Here's how it works:

1. Fuel and air are mixed within the engine's cylinder.

2. The mixture is ignited, causing a rapid expansion of hot gases.

3. This expansion pushes a piston, creating a force that turns a crankshaft.

4. The crankshaft's rotation is then used to power the vehicle's wheels or other machinery.

So, the chemical energy stored in the fuel is converted into heat energy by combustion, and then the heat energy is converted into mechanical energy by the engine.