How Wings Create Lift
What is the upward force that helps an airplane rise?
Lift
What is the distance from one wingtip to the other called?
Wingspan
What is the side-view shape of a wing called?
An airfoil
What is the front edge of a wing called?
The leading edge
Name one material that could be used to make a classroom airfoil
Paper, cardstock, cardboard or an index card
Which direction does a wing push air to help lift the airplane?
Downward
What is the angle between a wing and the air flowing toward it called?
Angle of attack
What classroom tool can provide moving air for an airfoil test?
A fan
What is the back edge of a wing called?
The trailing edge
Which part of a typical airfoil is usually more curved--the top or bottom?
the top
Air moving over and under a wing creates difference in what?
Air pressure
What usually happens to lift when the angle of attack is increased slightly?
Lift increases
For a fair test, how many things should you change at one time?
One
What is the downward moving air behind a wing called?
Downwash
What could you use to observe the direction of airflow around your airfoil?
String, yarn, ribbon smoke or streamers
What four forces act on an airplane during flight?
Lift, weight/gravity, thrust and drag
What can happen when the angle of attack becomes too steep?
The wing can stall
If you change the airfoil's shape, what should stay the same during every test?
The fan speed and testing distance.
What happens when airflow separates from the top of a wing?
Lift decreases and the wing may stall.
How could you test different angles of attack without making a new airfoil?
Tilt the airfoil to different angles
What usually happens to lift when an airplane slows down too much?
Lift decreases
Why do gliders usually have long, narrow wings?
They create lift efficiently with less drag
Why should scientists test each airfoil several times?
To make the results more reliable.
What spinning air patterns form near the tips of airplane wings?
Wingtip vortices
One airfoil rises higher than another under the same test conditions. What does that evidence suggest?
The airfoil created more lift