Question

Hot air balloons rise because their density is less than the density of air, indicate which gas law explains this phenomenon and using that gas law ,explain why hot air has a lower density than an equal mass of cold air.

Answer 1

Charles law

This means that as temperature increases and the pressure on the outside remains the same the balloon expands and therefore the air inside the balloon becomes less dense than the air outside of it, therefore rising up. This happens because when gases are heated the molecules inside move faster and further apart thus their density gets lower the particles get excited and causes the ballon to have a low enough density in companrison to the outside