Hot air balloons are an excellent demonstration of forces due to differences in density. The less dense hot air inside the balloon causes a buoyant force (upthrust) due to Archimedes’ Priniciple.
Tag Archives: density
Floating on air
Less dense things will float in more dense things; like cork floating in water or helium floating in air.
In the video above an aluminium foil boat floats on sulphur hexafluoride (SF6), a very dense gas.