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Name Things that you know can fly!
But...
How do they do it?
Paper Experiment
When you blew across the strip of paper, you lowered the air pressure by making the air above the strip move faster than the air below the strip.
With lower pressure on top compared to below, lift was created and caused the paper to rise.
hold one end of a strip of paper against your lower lip. Blow hard across the top of the paper and watch the paper strip rise.
Which force have you created? How did you create it?
Airplanes
- To fly, airplanes need engine power to provide thrust, which pushes the airplane forward.
- Friction against the rushing air produces drag, which holds the aircraft back.
- Lift from the wings pulls up on the aircraft.
- Aircraft's weight simultaneously pulls it down
Flight
Birds have wings and powerful muscles that enable them to fly.
Flapping provides a force called thrust - which moves a bird forward through the air.
A bird's wings are a special shape, called an aerofoil.
Aerofoil - the top side is more curved than the underneath.
This helps to keep a bird up in the air; even when it's wings are not flapping.
Lift
The Aerofoil
As air moves across an aerofoil wing, the curved top surface of the wing creates less air pressure above than below the wing. This difference in air pressure is called lift.
Direction of air movement
Lift:
When an aerofoil wing moves through the air, it creates an upward push.
This push is a force called lift.
It counteracts the weight of the object, which pulls the object down toward the ground
Birds, gliders, airplanes all have aerofoil wings!
Rotation
Helicopters have long, thin aerofoil wings called rotor blades.
Air Resistance
Powerful engines whirl the blades to produce lift.
They can hover, fly forward, backward sidways, up and down.
The plot can position the angle of
the blades to control lift and make the helicopter go in any direction
Things that fly have to push their way through the air (like we do in water when we are swimming)
Air clings to their surfaces as they rush through it.
The result is a backward pull called drag or air resistance.
Drag is a force that works against the direction of flight of anything that is flying through the air.
The amount of drag can be affected by shape:
Fat, lumpy shapes with sharp edges have a lot of drag
Sleek, streamlined shapes have low drag
Either way drag increases with speed
The drag limits how fast, aircrafts, birds, and insects can fly and increases the amount of thrust needed.
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