Answer :
Final answer:
The lifting power of a balloon depends on the principle of buoyancy and is determined by the difference between the mass of cold air displaced by the balloon and the mass of the hot air inside it. The density of the gas inside a hot air balloon in flight is less than the outside atmosphere, and the pressure is designed to be approximately equal to the atmospheric pressure.
Explanation:
To determine the lifting power of a balloon, one must understand the principle of buoyancy which is governed by Archimedes' principle. In the context of a hot air balloon, the lifting capacity is the difference between the mass of the cold air displaced by the balloon and the mass of the hot air inside it.
An average balloon with a volume of 1.1 × 105 ft³ displaces that amount of colder atmospheric air. The weight of this volume of colder air is its density times its volume, and the density of air at sea level is approximately 0.08 lb/ft³. The mass of the hot air is generally less because it is less dense, which is what makes the balloon rise. The capacity for the balloon to carry passengers and cargo is the difference between this lifting force and the weight of the balloon and its rigging.
With regards to the density of the gas inside the balloon, it is typically less than the density of the outside atmosphere when the balloon is in flight. This is because the gas inside the balloon is heated, making it expand and become less dense. As for the pressure inside the balloon, it is designed to be approximately equal to that of the atmosphere to prevent the balloon from bursting.
