Science - How do Hot Air Balloons Fly?

What is a hot air balloon?

A hot air balloon is a big balloon that carries people and supplies, and is powered by chemical energy. The fire produces gas fuel which heats up the balloon. To see how this works, try this experiment. Take a balloon and a working hair dryer. Put the balloon onto the hair dryer. Turn on the hair dryer. Watch the balloon blow until it gets big (for a normal balloon). Then, tie the balloon and watch it fly up up and away. A normal balloon with cold air wouldn’t do this. The hot air is what helps lift up the balloon, which helps lift up basket, where the supplies and/or people are.

Create a simple diagram of a hot air balloon and label at least 5 parts.

How do hot air balloons rise into the air?

Hot air balloons rise into the air because of the burners. The burners create heat and/or fire, which heats up the balloon. Cold air cannot lift up the balloon because the molecules are moving pretty slow compared to the hot air molecules. Because the hot air molecules move around a lot, the molecules go up and higher, causing the hot air to pull the balloon up.

How can hot air balloons be brought back down to the ground?

Hot air balloons can be brought back down to the ground by turning off the burners and controlling the parachute valve. The cold air that comes when you turn off the burners causes the balloon to descend, and the parachute valve lets both the hot and cold air out.

What are some of the ways people use hot air balloons?

Some of the ways people use hot air balloons are using them for transporting items/materials/cargo/loads, and to carry people.

Which of the 4 forces of flight do hot air balloons rely on the most?  Why do you think that?

Of the 4 forces of flight, I think hot air balloons rely mostly on the force of lift. I think this because, first of all, hot air balloons aren’t used for speed. They have no engines that can control the thrust. It couldn’t have been drag or gravity either, because they are negative forces. The only one left is lift, and hot air balloons were created to lift themselves up, and just slowly fly around in the air. Without lift, the hot air balloon would be useless and pointless. This is why I think hot air balloons rely on the force of lift the most.

Answered by:

Amanda (amyeducationalblog.blogspot.ca)