WeatherCâu 69 / 100
You launch a multirotor from a 6,500 ft mountain site on a 95 °F afternoon. What performance change should you expect?
a.Propeller efficiency improves because thin air offers less resistance
b.Battery voltage rises in thin air, giving noticeably longer endurance
c.Lift increases because the warm air rising around the aircraft helps it climb
d.Propellers produce less thrust, reducing climb rate and shortening flight time
Giải thích
High elevation plus high temperature means high density altitude, so the propellers move fewer air molecules per revolution and generate less thrust, which slows the climb, lengthens the takeoff run for fixed-wing UAS, and drains the battery faster for a shorter flight. Thin air does reduce drag slightly, but the loss of thrust dominates, so efficiency drops rather than improves. Density altitude has no effect on battery voltage, and localized warm air does not reliably add lift to a small UAS.
Luyện miễn phí toàn bộ 100 câu hỏi — không cần đăng ký.
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Đội Ngũ Biên Tập PrepPass · Đối chiếu với FAA Part 107 Remote Pilot Certificate Knowledge Test · Quy trình kiểm tra