Question: An airplane, whose air speed is 600km/h is supposed to flyy in a straight path 35 degrees north of east. But a steady 100 km/h wind is blowing from the north. In what direction should the plane head? Here is an answer by someone(is it right?) Vp (vector velocity of the plane) = 600cos35i + 600sin35j Vw (vector velocity of the wind) = -100j The direction in which it shud go is the direction of the velocity of the plane relative to the wind, Vpw As a rule Vpw= Vp - Vw => Vpw= 491.5i + 344.1j + 100j = 491.5i + 444.1j |Vpw|= 662.4 km/h (speed at which the plane heads, direction is given by tanA=j/i=444.1/491.5) tanA = 444.1/491.5 A = 42 degrees. The plane shud head East42North.