7. A small, private airplane is carrying three passengers to an island. The plane is 0.9 km in the air. If the potential energy of the plane and its three passengers is 48,510,000 J, what is the combined mass of the plane and its passengers? Round your answer to the tenth place. 8. If the plane from question 7 has a mass of 5,275 kg, and all three passengers have the same mass, what is the mass of each passenger?

Awelder using a tank of volume 7.50×10^-2 m^3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.30×10^5 pa and temperature of 37.1 ∘c. the tank has a small leak, and in time some of the oxygen leaks out. on a day when the temperature is 23.1 ∘c, the gauge pressure of the oxygen in the tank is 2.00×10^5 pa . a) find the initial mass of oxygen. b) find the mass of oxygen that has leaked out.