Some rear-view mirrors produce images of cars behind you that aresmaller than they would be if the mirror were flat. are the mirrorsconcave or convex? what is a mirrors radius of curvature if cars20.8 m away appear 0.33x their normal size?

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.