In 0.369 s, a 14.2-kg block is pulled through a distance of 3.60 m on a frictionless horizontal surface, starting from rest. The block has a constant acceleration and is pulled by means of a horizontal spring that is attached to the block. The spring constant of the spring is 491 N/m. By how much does the spring stretch?

constant acceleration? That means constant force...which means the spring cannot have a force kx, dependent on stetch.

Something is amiss here...