A horizontal spring is lying on a frictionless surface. One end of the spring is attached to a wall, and the other end is associated to a movable object. The spring and object are compressed by 0.056 m, released from rest, and subsequently oscillate back and forth by an angular frequency of 10.8 rad/s. What is the speed of the object at the instant when the spring is stretched with 0.047 m relative to its unstrained length?