An airplane flies 160 km at a constant altitude in a direction 30.0° north of east. A wind is blowing that results in a net horizontal force on the plane due to the air of 2.40 kN in a direction 10.0° south of west. How much work is done by the air on the plane?

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Quizplus · Accepted Answer

The work done by the air on the plane is negative because the force due to the air is in the opposite direction to the displacement of the plane. The magnitude of the work done is:$$W = Fd\cos	heta = (2.40	ext{ kN})(160	ext{ km})(10^3	ext{ m/km})\cos(180\degree + 10.0\degree + 30.0\degree) = -3.61	imes10^8	ext{ J}$$

An Airplane Flies 160 Km at a Constant Altitude in a Direction