A plane flying at a relative velocity to the air at 30m/s S into a headwind of 3.5m/s N relative to the ground. Suddenly the pilot spots a mob of kangaroos 2.0Km away heading south at 13m/s relative to the ground. (a) What is the velocity of the plane relative to the kangaroos? (b)How long would it take the pilot to reach the spot where he first spotted the kangaroos? (c) How long after the first sighting of the kangaroos, will the plane take to reach the mob?