A car moves forward through the application of force from the engine and transmission system. Here’s a brief overview of how a car’s propulsion system works:

1. The engine converts the chemical energy of fuel into mechanical energy. This is typically done through the controlled combustion of a fuel-air mixture inside the engine’s cylinders.

2. The engine’s crankshaft transforms the reciprocating motion of the pistons into rotational motion.

3. The transmission connects the engine’s rotating crankshaft to the car’s drive wheels. It uses a system of gears to either increase or decrease the rotational speed and torque delivered to the wheels.

4. When the driver presses the accelerator pedal, it signals the engine to increase its output. More fuel is injected, and the engine speeds up.

5. The increased rotational force from the engine is then transferred through the transmission to the drive wheels, causing them to rotate and propel the car forward.

The amount of forward force, or “tractive effort,” delivered to the wheels depends on factors like the engine power, gear ratio, tire grip, and vehicle weight. By controlling the throttle, the driver can regulate how much power is delivered to the wheels, allowing them to control the car’s acceleration and speed.