If two forces acting on an object act in the same direction then the net force or combined force can be found by adding the two forces together.

If the two forces act in opposite directions on an object then the net force is found by subtracting the smaller force from the larger force. The pair of forces are said to be unbalanced.

If the two forces are equal in size and act in opposite directions on the object then the net force is zero. The pair of forces are said to be balanced.