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## Homework Statement

You are traveling on an airplane. The velocity of the plane with respect to the air is 110 m/s due east. The velocity of the air with respect to the ground is 39 m/s at an angle of 30° west of due north.

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

## Homework Equations

None.

## The Attempt at a Solution

Ok, so I already obtained the speed by finding ##\vec V_{ag} = -39\cos(30^\circ)\hat i + 39\sin(30^\circ)\hat j##, and then adding it to ##\vec V_{pa} = 110\frac{m}{s}\hat i##, yielding ##V_{pg} = 95.73\frac{m}{s}##. The component form is ##\langle 76.23 , 19.5 \rangle##.

I then evaluated ##\arctan(\frac{19.5}{76.23})##, giving me ##\theta = 14.35^\circ##.

I don't understand where to go from here. What do they mean by letting "##0^\circ## represent due north" and "##90^\circ## represent due east"?

Thanks.