Automobile

Before examining the components of each system, it is useful to understand how the systems interact. The human body is again a good example of the interaction of systems. The heart pumps blood, which feeds the tissues of the body while at the same time helping to remove impurities. The tissues, fed by blood, are able to perform their tasks, and often are required to support the action of the heart. Muscle tissue, for example, depends on the availability of oxygen-rich blood from the heart in order to move the body.

The internal combustion engine is the heart of the automobile. The engine produces energy from fuel and converts that energy into the power to move the different components that will move the car. The engine converts the chemical energy produced by the burning of the fuel into mechanical energy. This energy is used to spin a shaft. The spinning shaft, through the interaction of the transmission and other components, causes the wheels to turn and the car to move. A similar transfer of energy to motion can be seen when bicycling. The up and down motion of the feet and legs is converted to the turning motion of the pedals, which in turn pulls the chain that causes the rear wheel to spin.

Just as it is more difficult to pedal a bicycle from a standstill than it is while already rolling, the engine requires the electrical system to give it the push to move on its own. The electric starter motor of an automobile provides a powerful force to give the engine its initial movement. The battery supplies energy for the engine to use when burning the fuel needed to make it run. The alternator is driven by a belt attached to the engine, recharging the battery so there will be a constant supply of energy. The sensors of the computer control system, which governs many of the processes in an automobile, also require electricity.

The burning of fuel is a hot, noisy process that also produces pollutants in the form of exhaust. This exhaust must be carried away from the engine and away from the automobile. The exhaust system, with its muffler, also acts to reduce the noise produced by the vehicle. Burning fuel in the cylinders produces two other results: friction and extremely high temperatures. In order to protect the parts from being worn down from the friction and from melting with the heat, they must be properly lubricated and cooled. These systems depend on the engine and the electrical system for the power to perform their tasks.

The engine's power is used to turn the automobile's wheels. Because the tires are the only parts of the automobile that are actually in contact with the road, they must rest on a system of supports that will carry the weight of the car and respond to conditions of the road surface. At the same time, the driver must be capable of guiding the direction of the automobile. Once an automobile is moving, it will continue to move until some sort of friction, the brake, is applied to stop it.

The wheels, suspension, steering, and braking systems are all attached to the car's chassis, as is the rest of the automobile. The chassis and body, analogous to the skeletal structure in the human body, provide support for all the various systems and components, while also providing safety, comfort, and protection from the elements for the automobile's passengers.