Paragraph on “How do jet engines work?” complete paragraph for Class 9, Class 10, Class 11 and Class 12

How do jet engines work?

Propeller engines like those on early planes worked like screws. They gripped the air and pulled the aircraft along.  Jet engines are quite different. They use a very simple but very important fact. If you stand on a sheet of ice and throw something- heavy away from you will find that you slide in the opposite direction as you throw. This ‘reaction’ always happens. Sir Isaac Newton, in the seventeenth century, wrote it down in his third law of motion : ‘For every action there is an equal and opposite reaction’. The jet engine uses this idea. It shoots hot gases backwards at high speed and therefore thrusts the aircraft forwards.

The details of a jet engine are shown in the picture below. Air comes in through the air intake and is squeezed by the compressor. Fuel is added and the mixture burnt in the ‘combustion’ or burning  chamber. The burning gases expand because they are hot and squirt out of the exhaust nozzle. As the gases shoot out backwards the engine is moved forward.