1. A large balloon used to sample the upper atmosphere is filled with 400 m³ of helium. What is the mass of the helium (in kg)?

2. Find the gauge pressure (in psi) at the bottom of a freshwater swimming pool that is 18.6 ft deep.

3. An empty storage tank has a volume of 9,470 ft³. What is the buoyant force exerted on it by the air? (Assume the air is at 0C and 1 atm.)

4. A modern-day zeppelin holds 9,760 m³ of helium. Compute its maximum payload at sea level. (Assume the helium and air to be at 0C and 1 atm.)

5. The wing of an airplane has an average cross-sectional area of 13 m² and experiences a lift force of 78,000 N. What is the average difference in the air pressure between the top and bottom of the wing?