Catapults

Let's begin by making a paper airplane.

There are many designs for paper airplanes, here is a new design that locks its shape into place using orgami techniques.

Paper airplane: Nakamura Lock.

Now that you have built a plane let's observe how it flies by measuring its glide ratio:

Measure glide ratio

Trim your airplane to achieve its best glide ratio, it will fly at some constant speed at this glide ratio.

If you throw the plane faster than this speed it will climb, slower it will dive.

On a runway aircraft use thrust from their engines to achieve flight speed. On a long runway they can use thrust to accelerate to speed over a long distance.

However, on a short runway aircraft may need an extra source of thrust. On an aircraft carrier this thrust is provided by a catapult.

A commercially available Electric Plane Launcher can be used as a catapult.

It is available from the Exploratorium Store as of 2008.

You can use this catapult to propel a paper airplane at a fixed speed and launch angle over and over again to conduct controlled experiments on paper airplane design.

You can launch the same plane over and over again, on each flight measure where it hits the ground and record its range, this will give you a measure of the variability of each launch.

Math Root:

Measure the range, R, ten different times, find the average range by adding all the ranges and dividing by 10  Rav = sum for i = 1 to 10 (Ri)/N

Then measure the standard deviation sd = (sum for i = 1 to 10 (Ri - Rav)^2/N)^0.5 the standard deviation will give you an idea of the error in each measurement due to your system.

Here is an activity on paper airplane design and flight.

Paper Airplane Science

Here is an essay on the forces which produce lift for airplanes.

The source of lift

There is a great NASA website on aircraft flight:

The Beginners guide to Aerodynamics : http://www.grc.nasa.gov/WWW/K-12/airplane/bga.html

You may also build flying planes from styrofoam plates.

Flying styrofoam plates

And investigate air resistance by dropping basket type coffee filters

Terminal Velocity

 Scientific Explorations with Paul Doherty © 2008 20 October 2000