The folks at Newton's Apple wrote the following!
People have always wanted to fly. Leonardo da Vinci, who often dreamed about flight, drew intricate designs for several different flying machines. Among the many scientists whose discoveries made human flight a reality are Sir Isaac Newton (1642-1727) and DanielBernoulli (1700-1782). Both are credited with developing the scientific principles that explain how an airplane flies. However, it was not until many years later, on December 17, 1903, that Orville and Wilbur Wright actually applied these principles to successful airplane flight. Their first flight lasted only 12 seconds, and they traveled only 120 feet. The entire trip could have taken place inside of a 747.
Thrust is the forward movement of the airplane, provided by the propellers or jet engines. Drag is the opposing force of the displaced air, the same force you feel walking into a strong wind. Gravity acts on the airplane, giving it weight. Lift counteracts the weight of the plane, keeping the airplane up in the air. The lift force is equal to the weight when an airplane is in level flight.
Whether a single-seat propeller plane or a giant 747, there are four fundamental forces at work in airplanes.
Bernoulli's principle helps to explain lift. Bernoulli demonstrated that the faster a fluid moves, the less pressure it exerts. An airplane wing is shaped so that air (which is a fluid) moves faster over the top of the wing than it moves under the bottom of the wing. As a result, there is greater pressure underneath the wing than there is on the top of the wing, resulting in a net force which "lifts" the wing.
the angle of attack) also contributes to lift. You can easily demonstrate this when you hold your hand out the window of a moving vehicle and change the angle at which your palm meets the oncoming air. If the surface of an airplane wing meets the air at an angle, the wing exerts a force on the air and the air exerts an equal force on the wing--an effect that Newton described in his third law of motion. There are many other factors that influence lift: the shape and area of the wing, the velocity of the airplane, and even the density of the air.
The angle at which the wing meets the air (
1. When you turn on the water to take a shower, why does the shower curtain move?
2. What different shapes of airplane wings can you think of? Why are they different?
3. How are the wings of birds like the wings of airplanes?
* hair dryer with a cylindrical nozzle
* Styrofoam ball, 4-5 cm in diameter (1 1/2" - 2")
* a couple of cardboard boxes of different sizes
1. The player sits in a chair or on a stool with the hair dryer "gun" about 1 meter (1.1 yds) away from the target box.
2. Place the smaller cardboard box inside a larger cardboard box to serve as the target. (Or cut and shape cardboard into curved sections and place in box, as illustrated below.) If you position the back of the box against a wall, you won't have to chase as many stray balls.
3. Scores for each part of the target are:
* inner box 3
* outer box 1
* outside of boxes 0
4. Use the hair dryer on the cold-air setting. If there are low- and high-speed settings, use the low speed.
5. Each player is allowed five practice shots and five shots for official score.
6. To start the game, turn the dryer on and point the nozzle straight up. Place the Styrofoam ball in the airstream about 30 cm (1') above the nozzle.
7. The player shoots the ball by smoothly tilting the dryer so that the ball falls out of the airstream and continues on a curved path toward the target.
8. If the ball hits the dryer, the player gets to try again.
* Anderson, J.D., Jr. (1985) Introduction to flight. New York: McGraw-Hill.
* Smithsonian Museum's Air and Space magazine PO Box 53261 Boulder, CO 80301 (800) 766-2149
* Aircraft Owners and Pilots Association 421 Aviation Way Frederick, MD 21701 (301) 695-2000 (free packet: A teacher's guide to aviation)
* Federal Aviation Administration 800 Independence Ave. SW Washington, DC 20591 (202) 366-4000
* NASA Education Division Mail Code F Washington, DC 20546 (402) 358-1110
* Society of Automotive Engineers Education Program Coordinator 400 Commonwealth Drive Warrendale, PA 15096-0001 (412) 276-4841
Length: 232 feet
* Height: 63 feet
* Wingspan: 211 feet
* Wing area: 5,650 square feet
* Empty weight: 538,000 pounds
* Maximum takeoff weight: 870,000
* Maximum landing weight: 630,000 (which explains why planes often need to dump fuel to make emergency landings)
* Engines: 4
I happen to fly a lot on business. For me, personally, airplanes are one of the most amazing things that I see on a daily basis. When I get on a 747, I am boarding a gigantic vehicle capable of carrying 500 or 600 people. A 747 weighs up to 870,000 pounds at takeoff. Yet it rolls down the runway and, as though by magic, lifts itself into the air and can fly up to 7,000 nautical miles without stopping. It is absolutely amazing when you think about it!