Ahockey player is wearing ice skates and pushes against the wall propelling her backward on the ice. according to newton's third law of motion, which of the following best compares the forces acting between the wall and the hockey player?

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?