A pilot wants to fly directly north to an airport 500 km away. His speed relative to the air is 100 km/h. Howevere there is a 40 km/h cross wind blowing from west to east. At what angle relative to the south north direction should he fly to arrive at the distant airport? How long will it take to reach the airport?

Question

A pilot wants to fly directly north to an airport 500 km away.  His speed relative to the air is 100 km/h.  Howevere there is a 40 km/h cross wind blowing from west to east.  At what angle relative to the south north direction should he fly to arrive at the distant airport? How long will it take to reach the airport?

Henry · Answer

Vp + Vw = 100i Vp + 40 = 100i Vp = -40 + 100i = Velocity of the plane Tan A = 100/-40 = -2.50 A = 111.8o CCW = 21.8o W of N d = V*t = 500 km t = 500/V = 500/100 = 5 h.