For a moving object, the force acting on the object varies directly with the object's acceleration. When a force of 81 N acts on a certain object, the acceleration of the object is 9 /ms2 . If the acceleration of the object becomes 2/ms2 , what is the force?

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?