Aerodynamics

Principles:
- A glider moves through the air without the help of a motor or engine
- A glider can move through air and descend gently

Facts:
- Design of wing and glider body has a major contribution to how it glides in the air
- Adding some weight to parts of glider will help it stay up in the air, have lift, and travel in a straight path (rather than spinning or nosediving)

This is a basic glider (paper airplane)

So how does it fly??

In flight, the glider has three forces acting on it (compared to the four forces that act on a powered aircraft). Lift, drag, and weight (since there is no engine for there to be thrust).

In order for the glider to fly, it must generate lift to oppose its weight. To generate a lift, a glider must move through the air. However, there is no thrust to oppose the drag as the glider moves through the air, therefore a glider quickly slows down until it can no longer generate enough lift to oppose its weight.

Even though a glider does not have thrust during flight, it has an initial velocity (coming from the person exerting force upon the glider [throwing the aircraft]). That's where the velocity needed to drive the aircraft comes from.

For a glider to remain up in the sky for a long time, it must be efficient and pass over any nearby updrafts (rising air).