Question

Edward travels 150 kilometers due west and then 200 kilometers in a direction 60° north of west. What is his displacement in the westerly direction?

Answer 1

     We must decompose the displacement vector to find the new displacement to the west.

$d_{x}=v.cos\O \\ d_{x}=200. \frac{1}{2} \\ d_{x}=100km$
  
     Adding all displacements to West, It comes:

$\Delta S= d_{o}+d_{x} \\ \Delta S= 150+100 \\ \boxed {\Delta S= 250 km}$

If you notice any mistake in English, please let me know, because I'm not native.