Machines 6 Gasoline Jet Engines 1 A car

Machines 6. Gasoline & Jet Engines 1

A car is a compound machine It is made up of many simple machines 2

One of the most important parts of a car is its engine Vocabulary: engine A compound machine 3

In most cars the engine gets its energy from gasoline Gasoline is a fuel 4

Engines that use gasoline as their fuel are called gasoline engines A gasoline engine has up to eight tubes called cylinders 5

The engine also has a carburetor where gasoline is mixed with air The carburetor sends this mixture to the cylinders 6

Some gasoline engines do not have carburetors Instead a fuel-injection system squirts fuel into the cylinders 7

Each cylinder has its own spark plug When the mixture of gasoline and air reaches the tops of the cylinders the spark plugs start little fires 8

The gases from the fires push on pistons inside the cylinders The pistons move up and down 9

The up-and-down motion of the pistons moves another part of the engine called a crankshaft 10

The motion of the crankshaft gives the energy the car needs for the wheels to turn and for the car to move 11

Gasoline engines are not only in cars. They can also be used in lawn mowers, small boats, trucks, and propeller airplanes 12

Most large airplanes today are powered by jet engines Jet engines are compound machines 13

Air goes into the jet engine A compressor squeezes the air, which is then mixed with fuel 14

The fuel mixture burns and produces hot gases The gases turn a turbine wheel that runs the compressor 15

Then the gases rush out of the engine toward the tail of the plane 16

Jet engines work because of one of the laws of motion Remember that for every action there is an equal and opposite reaction 17

The action is gases rushing out of the engine The reaction is the motion of the plane in the opposite direction 18

The gases do not need any matter to push against Even without air, a jet plane would fly 19

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