A mass sitting on a horizontal, frictionless surface is attached to one end of a spring; the

Question:

A mass sitting on a horizontal, frictionless surface is attached to one end of a spring; the other end is fixed to a wall. 3.0J of work is required to compress the spring by 0.12 m. If the mass is released from rest with the spring compressed, the mass experiences a maximum acceleration of 15m/s2. Find the value
(a) The spring stiffness constant and
(b) The mass.