What hot springs in the ocean floor

What is the coefficient of kinetic friction μk between the block and the tabletop?

Coal contains energy. a. light b. kinetic c. chemical d. mechanical

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?