A balloon is a cylindrical or a spherical body made up of rubber, silk, rubberised fabric or paper. It inflates when hot air, hydrogen or helium is filled in it. These three gases are lighter than normal air. Hence, when they are filled into the balloon, the balloon rises in the air. Another factor that helps the balloon rise is the weight of the balloon and the attached accessories (basket, strings, etc). When the balloon and all its attached accessories weigh less than the volume of air that it displaces, it rises in the air. The balloon, once released, rises up to a level where the weight of air that it has displaced is the same as its own weight.
What Makes a Balloon Rise?
