A helicopter flies south at 185km/hr relative to the ground. The wind is blowing 60km/hr to the west compared to the ground. What is the helicopter's speed to an observer on the ground?

Answer 1

y component = -185
x component = -60

speed = sqrt(185^2 + 60^2)

tan angle south of west = 185/60
angle south of west = 72

72+180 = 252 in math convention counterclockwise from +x axis

270-72 = 198 in navigation convention clockwise from north (about SSW)