1. The problem statement, all variables and given/known data A hot-air balloon has a volume of 1.5m^3 and is open at the bottom. If the air inside the balloon is at temperature of 75C, while the temperature of the air outside the balloon is 24C, at a pressure of about 1 atm, what is the net force on the balloon and its contents? (Neglect the Weight of the balloon itself). 2. Relevant equations 3. The attempt at a solution I know that this question is about the ideal-gas law, but for some reason I just can't think how to do it.