Math 11F

A cargo jet leaves an airport that is 3000 ft above sea level at 7.15 p.m. The jet climbs steadily to a cruising altitude of 35 000 ft, at a rate of 4000 ft/min. After cruising at this altitude for 70 min, the jet descends steadily at a rate of 5500 ft/min to an airport that is 1500 ft above sea level. What time does the jet land? Show your work. ................
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