Question

A plane in calm weather flies east at 20 K.P.H. A 45 K.P.H wind blows from the north. Find the direction and speed required to keep the plane in it's original course and speed.

Answer 1

You want <x,y> such that

<x,y> + <0,-45> = <20,0>
clearly that is

<20,45>

Now just convert that to speed and direction.