Solve the all parts of following problem given below:
Problem: The Kitty Hawk was the first balloon to traverse the North American continent. It was filled with 200,000 cubic feet of helium for its sea level take-off on a 10 deg C evening at Fort Baker, California, May 7, 1980. Because the balloon envelope is thin and flexible, the helium inside remains in equilibrium with its surroundings at zero gauge pressure, and at the same temperature as the surrounding atmosphere,
Part A: Calculate the mass and weight of the helium at take-off conditions?
Part B: Calculate the buoyant force experienced by the craft at take-off?
Part C: What would be the "dry weight" (not counting the helium) barely sufficient for take-off assuming static equilibrium?
Part D: What volume would the helium mass found for take-off occupy at an altitude of 20,000 ft under standard conditions?
Please give a full detailed explanation of solution for above problem.