Orville and Wilbur Wright were two American brothers who liked to build things. One of the things that they built was the world’s first successful airplane back in 1903.
Forty one years later, the Germans built the V-2 Rocket, which is the first rocket to reach space.
For both of these events, propulsion played a big part.
For an object to gain forward thrust, a large amount of pressure needs to be released backwards. This is what our fellow scientist Newton states, which is that every action has an equal reaction in the opposite direction. Ever noticed a pistol or rifle jerking backwards when being shot? The same rule applies.
One of the ways of producing large amounts of energy under high pressure is by mixing fuel with oxygen. This pressure is released backwards through a nozzle that is smaller than the chamber where the combustion took place, creating a reaction that propels the airplane or rocket forward or upward. For a rocket to propel from the Earth’s surface towards outer space, it needs to travel at an astounding speed of 27,650 km/h!
Birds, on the other hand, propel their bodies forward by flapping their wings. The Spine-tailed Swift is the fastest-flying bird in flapping flight, being capable of speeds up to 170 km/h! At this speed, this bird can travel from KLCC to KLIA in twenty minutes!
Experiment: Propulsion by high-pressured air
Materials
balloon, string, drinking straw and sticky tape.
Steps:
1. Cut a 1 meter length of string.
2. Thread the string through the drinking straw.
3. Attach the string ends to opposite side of the room. Make sure the string is taut.
4. Blow up a balloon and clip the end. Do not tie it.
5. Sticky tape the balloon to the straw and position it at one end of the string.
6. Release the clip and watch what happens.
7. Increase the incline of the string and repeat steps 4 to 6
Glossary of terms:
Propulsion [pruh-puhl-shuhn] the act or process of propelling
Thrust [thruhst] to push with force
Combustion [kuhm-buhs-chuhn] the act or process of burning
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