Answer:
The second vector [tex]\vec{F_2}[/tex] points due West with a magnitude of 600N
Explanation:
The original vector [tex]\vec{F_1}[/tex] points with a magnitude of 200N due east, the Resultant vector [tex]\vec{R}[/tex] points due west (that's how east/west direction can be interpreted, from east to west) with a magnitude of 400N. If we choose East as the positive direction and West as the negative one, we can write the following vectorial equation:
[tex]\vec{F_1}+\vec{F_2}=\vec{R}\implies\vec{F_2}=\vec{R}-\vec{F_1}=-400N-200N=-600N[/tex]
With the negative sign signifying that the vector points west.
