You are trying to find the gravitational acceleration of an element and you are given the force (weight) as 2N and the mass as 45000 oz. Newton's second law of motion states:
F = ma
So that means you can solve for a and plug in your values. Don't forget to convert all your units to something manageable, though. It works well if you convert the mass to kg, then calculate acceleration in m/s2, then finally convert that to inch/hr2 (that's a strange unit!)
Hope this helps,
Stephen La Rocque.