You are piloting a small plane that can maintain an air speed of 136.5 kt (knots, or nautical miles per hour) and you want to fly due north (azimuth = 000°) relative to the ground.
(a) If a wind of 31.5 kt is blowing from the east (azimuth = 090°), calculate the heading (azimuth) you must ask your copilot to maintain.
(b) At that heading, what will be your ground speed?