Lighter-Than-Air Flying Devices. Background. Vehicles designed to travel through air are termed aircraft. There are two types of aircraft: 1. those that fly through the air 2. those that float in air. Hot air balloons and helium airships float in air.
Buoyancy is based on the idea that less dense objects will float in a more dense fluid.
Hot air balloons use propane tanks to heat the air in the envelope, or fabric part, of the balloon.
Hang two paper bags upside down and have a light source placed beneath one bag.
How could you control the balloon so that it did not float all the way to the ceiling?