The pilot should head 13.6° north of west.
Why?
We can solve the problem by using trigonometric relations. Since there is a right triangle formed between the direction that the pilot wants to fly to and the wind's speed, we can use the following formula:
[tex]Tan(\alpha )=\frac{WindSpeed}{PlaneSpeed}\\\\\alpha =Tan(\frac{WindSpeed}{PlaneSpeed})^{-1}=ArcTan(\frac{WindSpeed}{PlaneSpeed})\\\\\alpha =ArcTan(\frac{WindSpeed}{PlaneSpeed})[/tex]
Now, substituting the given information and calculating, we have:
[tex]Wind=75\frac{km}{m} (southward)\\\\Airplane=310\frac{km}{h}[/tex]
[tex]\alpha =ArcTan(\frac{WindSpeed}{PlaneSpeed})\\\\\alpha =\frac{75\frac{km}{h} }{310\frac{km}{h} }=13.6\°[/tex]
Hence, we have that the pilot should head to 13.6° north of west.
Have a nice day!