Question

A hot air balloon contained a large volume of air with a density of 0.0013 g/mL. After opening up the burner for an extended period of time, the air began to substantially heat up. Consequently, the spaces between the air particles became greater and the volume of the air in the balloon increased by 5%. If the mass of the air stayed pretty-much the same, what would be the density of the heated air in the balloon?

Answer 1

Answer: The density of the heated air in the balloon would be 0.00124 g/mL.

Explanation: The density of a substance is defined as its mass per unit volume. If the mass of the air in the balloon remained unchanged, but its volume increased by 5%, then the density of the air must have decreased by 5%. This means that the density of the heated air in the balloon would be 0.0013 g/mL * (1 - 0.05) = 0.00124 g/mL.