A small plane aims to fly directly east at 120. km/h, but a headwind is blowing 50. km/h at 22 degrees south of west, slowing the plane down. Find the plane's actual ground speed and direction.

Answer 1

Vr = 120km/h[0o] + 50km/h[202o,CCW].

Vr = 120+50*Cos202 + i50*sin202 =
120 - 46.4 - 18.7i = 73.6 - 18.7i, Q4.

Vr = 73.6 - 18.7i = 76[-14.2o] = 76km/h[14.2o] S. of E.