Answer:
Action force and Reaction force
Explanation:
The action force which is the balanced rock pushing down due to gravity and the reaction force pushing the equal amount of force. These two things are stated in Newtons third law, where he states that "Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first." Also, he states that "all forces acts in pairs," meaning that every force exerted, there is an opposite force on the first.
