Examples of balanced forces include the centripetal and centrifugal forces that keep the planets in fixed orbits around the sun, as well as weight and reaction forces that keep a book on a table. Balanced forces are forces that are equal in magnitude and opposite in direction.
The net force acting on a body when forces are balanced is zero. When forces cancel one another, the object the forces act upon is said to be in equilibrium. Balanced forces are what cause objects to tend to remain in their states of motion.
When the forces acting on a body are balanced, this does not necessarily mean the object is stationary. The object may be traveling at a constant velocity relative to a certain reference frame. However, the body cannot be accelerating or decelerating, as this would require the presence of a net force, according to Newton’s Second Law.
Weight and a corresponding reaction force from a solid surface are examples of balanced forces. A person standing on a floor is pulled downwards by the Earth’s gravitational field, causing them to exert a force equal to their mass times their acceleration on the floor. The floor reacts with an equal and opposite force, causing the person to remain in equilibrium.