A box with the mass of 74 kg is sitting on the ground and the bottom of the box measures 90 cm by 60 cm. What is the pressure exerted by the box on the ground?

Assume that a person skiing high in the mountains at an altitude of h = 15100 ft takes in the same volume of air with each breath as she does while walking at sea level. determine the ratio of the mass of oxygen inhaled for each breath at this high altitude compared to that at sea level. assume that the air composition (i.e. % of air that is oxygen) is the same at sea level as it is at 15100 ft.