A balloon filled with hot air at T=400K is released at sea level. Estimate the elevation h of the balloon above sea level when it stops rising. The balloon is made from an elastic material such that the pressure inside and outside the balloon can be considered equal. The weight of the balloon material is also negligibly small. Assume that the heat exchange between the balloon and the surroundings can be neglected. Assume that the temperature of the atmosphere is the same at all elevations and equal to Ta = 300K. The average molar mass of air is 29 g/mol and the molar heat capacity of air at constant volume is . Also assume that air is an ideal gas.