Five equal forces of 10N each are applied at one point and all are lying in one plane. If the angles between the successive force vectors are equal, the resultant of these forces will be 

The forces can be represented on a polygon as shown in the figure. Since the angles between the successive force vectors are equal the head of the last vectors are equal the head of the last vector joins the tail of the first vector. Therefore according to the polygon law, the resultant is zero