1. The problem statement, all variables and given/known data A mass is attached to the wall by a spring of constant k. When the spring is at its natural length, the mass is given a certain initial velocity, resulting in oscillations of amplitude A. If the spring is replaced by a spring of constant 2k, and the mass is given the same initial velocity, what is the amplitude of the resulting oscillation? 2. Relevant equations E = 1/2mv^2 + 1/2kx^2 = 1/2kA^2 3. The attempt at a solution I am not quite sure what equation to really apply here, or how to approach the problem to find the amplitude. The answer is 1/(√2).