Vector addition can be used to determine the net force. When a net force acts on an object, it accelerates in the direction of the net force. The relationship between the SI units for force and the corresponding fundamental units can be illustrated from Newton's second law. Newton's third law states that for every action force a reaction force exists which is equal in magnitude but opposite in direction to the action force. This can be illustrated using many common examples.
Forces exist in pairs.
If object A exerts a force on object B, then object B will exert a force on object A, equal in magnitude, but opposite in direction. There are a variety of ways of solving problems in physics. No one method is inherently superior to others, although some methods may have certain advantages in specific situations. To solve problems relating to force and motion, geometric methods using vector diagrams, trigonometry, or vector component methods are some different ways to arrive at similar results. Practice in problem solving leads to improved proficiency and a greater understanding of how forces interact with objects.