A spherical balloon is constructed of a material such that the pressure inside is proportional to the balloon diameter to the power 1.5. The balloon contains argon gas at 1200 kPa, 700C, at a diameter of 2.0 m. A valve is now opened, allowing gas to flow out until the diameter reaches 1.8 m, at which point the temperature inside is 600C. The balloon then continues to cool until the diameter is 1.4 m.
a) How much mass was lost from the balloon?
b) What is the final temperature inside?
c) Calculate the heat transferred from the balloon during the overall process.