4. A spring with a spring constant of 520 N/m hangs from the ceiling of a room. If a mass of 2.5 kg is placed on the end and the spring is allowed to stretch until it reaches static equilibrium, how far is the spring stretched from its equilibrium position? 5. If the spring and mass in problem 4 are placed horizontally on a flat, frictionless surface and one end of the spring is attached to a wall, how fast would the mass be traveling when it crossed the equilibrium position if it were displaced by 0.50 m from equilibrium and released from rest? What would the period of oscillation be