help me out with a relative motion problem

[coach94]

Ive been stuck on this problem for a bit, I'm not exactly sure what equation to use to solve it so any help pointing me in the right direction is appreciated!

 

You are traveling on an airplane. The velocity of the plane with respect to the air is 120 m/s due east. The velocity of the air with respect to the ground is 44 m/s at an angle of 30° west of due north.

 

what ive found : planes speed relative to the ground is 105.15 m/s

 

question i can't figure out :

 

1) What is the heading of the plane with respect to the ground? (Let 0° represent due north, 90° represents due east).

 

 

[mathematic]

The x coordinate of speed = 98 m/sec., the y coordinate is 22√3 m/sec. Therefore the angle is arctan (7.7155) (arctan(y/x) counterclockwise from 90 deg.