-200 N
Explanation
Step 1
we can see that on the object are acting vertical forces, if we assume the y-positive axis as positive ( upwards) then we have
[tex]\begin{gathered} \sum ^{\square}_{\text{xorce-in y}}=600N-800N \\ \sum ^{\square}_{\text{xorce-in y}}=-200\text{ N} \end{gathered}[/tex]
therefore, the answer is -200
