Automobiles are one of the most important parts of our life and it’s hard to imagine a modern world without them. They are a source of comfort and make our life easier, by providing us with the mobility to go anywhere we want to.
Cars are usually powered by an engine, which converts chemical energy into mechanical energy to turn the wheels of the vehicle. This energy can come from a tank of gasoline or an electrical battery. The amount of energy used is measured in kilowatts or horsepower. The engine also needs to work with other components such as a transmission and brakes. The transmission is responsible for changing the gears that change the speed of the motor and adjusts the torque output from the engine to the wheels. The brakes are also important to slow the automobile and they can be powered by friction or regenerative (turning the motion of the vehicle into electricity).
Some of the most popular models of automobiles are sedans, station wagons, pickup trucks, sports cars, and luxury vehicles. Passenger cars are the primary means of transportation worldwide and they cover more than three trillion miles (five trillion kilometers) each year on average. The modern automobile’s invention revolutionized public transport and introduced efficient methods of mass production. These innovations, along with cheaper gasoline and improved safety systems, made the automobile accessible to middle-class families in developed countries.