2 Ebgines

Practical machines are much more complicated than the simple machines discussed in the first chapter. If you look of parts that are simple machines, particularly levers, wheel and gears. All these parts work together to perform a particular task, such as making a car run. We can think of a car as being two machines in one. The first machine is the engine. This changes the energy in a fuel (usually gasoline ) into motion . The second car machine is the transmission, which transmits the motion produced by the engine to the wheels that drive the car. Machines, like a gasoline  engines ,that produce motion are called prime movers. We use several other kinds of prime movers, such as steam engines, jet engines, and tur- bines . Electric motors are also very  widely used to drive machines. They work by electricity produced by prime movers in power plants.