force third law

Force is a central concept in all of physics. It is a vector quantity – must describe the direction in which it acts as  well as its magnitude. A force is an action that produces a deformation and / or acceleration. The net force on a body is the sum of all forces acting on the body . we sometimes refer to the net force as the total force , the resultant force , or unbalanced force . when several forces act simultaneously on an object , the object accelerates only if the net force acting  on it is not equal to zero. When the velocity of an object is constant the object is said to  be in equilibrium