A billboard, mass 15 kg, is suspended from a roof by means of a light inextensible string. Force F pulls the billboard sideways, as shown in the diagram below.
40°
string
F
15 kg
When the angle between the roof and the string is 40°, a closed vector diagram is
obtained for all the forces acting on the billboard.
2.1
What deduction can be made when the forces acting on an object forms a
closed vector diagram?​