let's say a mass is hanging down from the ceiling at certain distance from the ceiling and say it's equilibrium distance is x from the ceiling when mass is at the rest. if k = 20N/m what is maximum distance that can be displaced from x when 250J is applied.. apparently I set 1/2 kx^2 = 250 and x = 5m but I thought it should be less than 5m because as the mass goes up doesn't the the gravity and spring both acts on the mass? So at equilibrium distance as it goes up, there is no force acting on it but as soon as it goes up beyond the equilibrium point, there is potential energy and elastic energy to count so that maximum distance should be less than that? so 250 = mgh + 1/2kx^2 which in this case x = h since they are basically the same? the answer says it's 5 m though from GS FL's. some questions from here are whacks. please clarify.