5. Airplanes
Drag
An aerodynamic force that resist the motion of an object
Through a fluid (air and water are fluids)
The amount of drag an airplane creates depends on:
•Size and shape of the plane.
•Speed of an airplane.
•Density of the air.
Landing gears are
retracted to reduce the
drag.
7. Airplanes
Aerodynamic force that holds an airplane in air.
Most of the lift required to keep the plane aloft is created by
the wings.
Lift
8. Airplanes
•Particles split at the leading edge, and they come together at the
trailing edge of the wing.
•Since the particles on top travel longer distance in same amount
of time, they must be traveling faster.
Bernoulli’s Theory: The speed of a fluid increases, its pressure
decreases.
•Faster moving air on the top creates a low pressure on the top.
•The low pressure on the top essentially “sucks” the plane wings
upward.
Longer Path Explanation
11. Airplanes
Angle of Attack
The angle that the wing presents to oncoming air, and it
Controls the thickness of the slice of air the wings is cutting off.
As it controls the slice, the angle of attack also controls the
amount of lift that the wing generates.
Zero angle Shallow angle Steep angle
12. Airplanes
To compensate for different speeds (Cruise speed 901Kph and
Landing speed 332Kph) Airplane wings are equipped with:
Flaps airplane wings have moveable sections at the trailing
edge .
•are extended rearward and downward
same function as Flaps, but attached at the front
of the wings
Slats
13. Airplanes
Propeller: provides the thrust that moves the plane forward
•Has an angle of attack
•Angle of attack changes along the length
of the propeller
•The angle is greater toward the center because
the speed of the propeller through the air is
slower close to the hub.
Some props have an adjustable pitch: propeller
Angle changes depending on air speed and altitude
14. Airplanes
Horizontal and Vertical Stabilizers
Tail of airplane has two small wings: horizontal and
vertical stabilizers.
Horizontal: Controls up and down
Vertical: Controls left and right
16. Airplanes
Elastic Band Airplane Facts:
•In 1909 American record for distance flown with a rubber
band powered airplane was just over 200 feet
•In 1916 , Thomas Hall flew his model plane 5337 feet
•In 1924, Robert V. Jaros flew a model 7920 feet in
10 minutes and 14 seconds
•Today model airplanes fly for over 40 minutes.