A mass of 130 g is held by a horizontal spring constant 22 N/m. It is displaced from its equilibrium position and released from the rest. As it passes through its equilibrium position, its speed is 4.2 m/s. a) find work done on the spring. w=1/2mv^2 1/2(.13kg)(4.2)^2= 1.14 (correct) b) what is the magnitude of the initial displacement? I dont know what to do for this , Im guessing were suppose to find distance but I dont know how.