Maybe I'm just losing it but I can't seem to find a way to reduce this equation to the terms it requires: A weight is suspended on the end of spring that is stiff enough to have no perceptible sag or bend and a equilibrium length of b. If the system is undergoing steady circular motion in which one rotation takes time T, create an equation to calculate the length of the spring in terms of b,T, and k (spring constant). I started out by making (M*4*pi^2*b)/T^2=k(L-b) where L is the current Length of the spring while under rotation and M is Mass. If I solve for L I get L=(M*4*pi^2*b+b)/T^2*k, but am unable to get rid of the M for Mass. I suspect that it could be canceled out by the mass component of k, but then that would not leave a k in the equation. Am I way off on this? Can it be expressed in only those three terms? Any help would be much appreciated.