The ground speed of an airplane that has an airspeed of 200 km/h when it is in a 200-km/h crosswind is
A) 200 km/h.
B) 283 km/h.
C) 0 km/h.
D) 1600 km/h.
E) 400 km/h.

Question

Quizplus · Accepted Answer

The ground speed of an airplane in a crosswind is found by calculating the resultant vector of the airplane's airspeed and the crosswind speed. Since the airspeed and crosswind are perpendicular to each other, you use the Pythagorean theorem: $\sqrt{200^2 + 200^2} = \sqrt{40000 + 40000} = \sqrt{80000} = 282.84$ km/h, which rounds to 283 km/h.

The Ground Speed of an Airplane That Has an Airspeed