Question

You are told that an object has zero acceleration. Two forces acting on the object ar f1=3.6N at 74 degress below the +x axis and f2=3.6N above the -x axis. What is the 3rd force on the object?

Answer 1

As both two forces are equal and directed oppositely, vector sum of them equals to zero. Thus there is no any additional force required to keep the object in the rest.