Around the summit of Mount Everest (altitude ~ 8400 m or 27600 ft, for reference, typical passenger plane cruising altitude is ~9400m or 31000 ft), the temperature is roughly 240K. The air pressure is roughly 0.3 atm. The oxygen content in the air decreases to around 10%. For a human consuming 500 W of power, what's the volume of air required each second? (Hint: human can bring in 5L of fresh air per breath. Assuming that human can only utilize half of the oxygen available in air, and can have 1 breath per 3 seconds, human cannot survive due to lack of oxygen at altitude 8400m)