Question

example of density
hot air balloons float due to a difference in density. hot air is less dense than cool air. heating the air inside the balloon creates a buoyant that pushes the balloon

Explanation:

Hot air balloons float because hot air has lower density than cool air. Heating air in the balloon creates buoyant force which lifts it. Buoyant force is based on Archimedes' principle where an object in a fluid is pushed up by a force equal to the weight of the fluid it displaces. In the case of hot - air balloons, the less - dense hot air inside the balloon displaces the more - dense cool air outside, resulting in an upward buoyant force.

Answer:

Hot air balloons float due to a difference in density. Hot air is less dense than cool air. Heating the air inside the balloon creates a buoyant force that pushes the balloon upward.