The breaking strength of a steel cable is 20,000N. If one pulls horizontally with this cable, what is the maximum horizontal acceleration which can be given to an 8000kg body resting on a rough horizontal surface if the coefficient of kinetic friction is 0.15?

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?