A pulsar is a celestial object that emits light in short bursts. A pulsar in the Crab Nebula flashes at a rate of 30 times/s. Suppose the light pulses are caused by the rotation of a spherical object that emits light from a pair of diametrically opposed flashlights on it equator. What is the maximum radius of the pulsar if no part of its surface can move faster than the speed of light?

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.