An observer, on a ship A sailing to the north with speed of 7km/h, saw a ship B. Ship B seems to be moving to south-east with a speed of 12√2 km/h.
Find the direction which B is heading to.
The Attempt at a Solution
Let i and j be the unit vectors in the direction of eat north respectively and VA = velocity of ship A and VB = velocity of ship B.
Now, VA = 7j
BVA = 12i - 12j
= BVA + VA
=12i - 5j
so θ = tan-15/12 = 22.6°
The direction of ship B is E22.6°S.
But the answer given is N67°23'E, which step is incorrect? Can anyone enlighten me?