Question

A 56 kg student is standing atop a spring in an elevator that is accelerating upward at 3.5 m/s^2. The spring constant is 2300 N/m. By how much is the spring compressed? I'm not exactly sure how to approach this problem, much less solve it. The acceleration threw me off, as my energy equations involve velocity. PEsp= 1/2k(delta x)^2, KE=1/2mv^2