I was wondering if any of you guys could solve this problem for me with complete solutions. I have been at it for a couple of hours and Im running out of pencil. I would really appreciate your help! Problem: A helium balloon is used to lift a load of 110 N. The weight of the balloon's skin is 50 N, and the volume of the balloon when fully inflated is 32 cubic meters. The temperature of the air is 0 degrees C and the atmos. pressure is 1 atm. The balloon is inflated with sufficient helium gas so that the net upward force on the balloon and its load is 30 N. Neglect changes of temperature with altitude. (a) How many moles of a helium gas are contained in the balloon? (b) At what altitude will the balloon be fully inflated? (c) Does the balloon ever reach the altitude at which it is fully inflated? (d) If the answer to (c) is affirmative, what is the maximum altitude attained by the balloon? P.S: Does anybody know if a guy named Paul Tipler is in the forums?