# Hot air balloon

### Hot air balloon

A hot air balloon is a balloon aircraft which is lifted by hot air.

Physics

Keywords

hot-air balloon, balloon, lift, aviation, gondola, gas burner, gas laws, rising, floating, descending, gravity, mechanics, force, thermodynamics, physics

Related items

### Forces and thermal conditions

• rising - buoyant force > weight
• floating - buoyant force = weight
• descent - buoyant force < weight
• buoyant force - It is equal to the weight of the air displaced by the balloon.
• weight - This is the force of gravity acting on the total mass of the hot air balloon. It points towards the Earth's centre of mass. The buoyant force must be greater than the weight of the aircraft to lift it.
• rigid frame - The basket is attached to the bottom of the frame (or directly woven onto it), while the envelope is attached to the top with steel cables.

### Structure

• basket - Also called a gondola, it is usually made of woven wicker or rattan as these materials are lightweight but strong and durable.
• envelope - It is made from non-elastic materials thus its size does not change when being filled with hot air.
• gas burner - It burns propane gas to heat the air in the envelope. There are at least 2 burners in a hot air balloon, for safety reasons.

### Related items

#### Hot-air balloon (18th century)

The French Montgolfier brothers were the first pioneers of flying.

#### Aerodynamic lift

Due to their asymmetrical profile of the wings, lift is produced while flying at a high speed.

#### Forces

The animation shows the way forces act on wheeled vehicles and vehicles with runners.

#### Newton’s Laws of Motion

This animation demonstrates Sir Isaac Newton's three laws of motion that laid the foundation for classical mechanics.

#### Submarine operation

Submarines submerge and surface by changing the average density of the hull.

#### Thermometers

There are various types of instruments used for measuring temperature.

#### Unmanned aerial vehicles (UAV)

The range of applications of unmanned aerial vehicles ('drones') keeps growing.

#### Wright Flyer I (1903)

The Wright Flyer was the first successful powered, heavier-than-air aircraft, designed and built by the Wright brothers.

#### Airport

Airports provide infrastructure and services necessary for aviation.

#### Meteorological instruments

This animation demonstrates instruments used to examine atmospheric phenomena.