Gravity is a pulling force that comes from very large and heavy objects, like planets.
What would happen if you blew cold air inside a hot air balloon while it was flying?
It would fall! Cold air sinks.
Air can be compressed, true or false?
True
Piston engines turn a set of small wings called ___________ to produce thrust
A propeller!
What did Bernoulli say about fast and slow air?
Faster air exerts lower pressure, slower air exerts higher pressure
For thrust to be generated in an engine, there has to be more pressure in the backward direction than the forward direction. True or false?
False!
Newton's third law says: If an object has a force going forward, there has to be an equal force going backward. What's a real life example of this?
...
Engines produce thrust by making a ____________ difference.
Pressure
What is a vaccuum?
A space with nothing in it (no air)
Air is constantly pressing on us in daily life, true or false?
True!
Racing cyclists often bend their head down low. Why do they do this?
Bending their head down reduces the area of their body that is exposed to the air. This means less air resistance, and less drag.
What is an airfoil?
The common shape of a wing, that helps it generate lift.
If I put a water bottle with a balloon over it into a pot of boiling water, what happens to the balloon? Why?
The balloon will fill with air, because the hot water will heat the air in the bottle, causing it to expand and fill the balloon.
What is this??
Vacuum sealed chicken!
In order for a helicopter to hover in the air, all four forces of flight have to be ____________
Balanced / Equal
What are the four forces of flight?
Weight, Lift, Drag, Thrust
How do wings generate lift?
The airfoil shape of a wing pushes air down and causes a pressure difference between the bottom and top of the wing.
What is air pressure?
the force of air on surrounding objects (higher pressure = more force)
Which plane will experience less drag, and why?
Drag is caused by air resistance, or the rubbing (friction) of air against the surface of an object. The more air can pass over the object, the less drag!
A balloon with air inside of it is heavier than a balloon without air inside of it, true or false
true!
What happens to air when you heat it up?
The air particles move faster, air expands, air becomes less dense, and air rises
What's an example of a flying aircraft with no engine?
glider, hang glider, flying squirrel, paper airplane, etc.
What kind of force do engines produce?
Thrust.
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