Work-Energy Theorem: an Unusual Spring Has a Restoring Force of Magnitude

Multiple Choice

Work-energy theorem: An unusual spring has a restoring force of magnitude F = (2.00 N/m) x + (1.00 N/m²) x², where x is the stretch of the spring from its equilibrium length. A 3.00-kg object is attached to this spring and released from rest after stretching the spring 1.50 m. If the object slides over a frictionless horizontal surface, how fast is it moving when the spring returns to its equilibrium length?

A) 2.06 m/s
B) 4.33 m/s
C) 3.27 m/s
D) 5.48 m/s
E) 1.50 m/s