1. The problem statement, all variables and given/known data The total energy of a spring-mass system oscillating horizontally is 1600 J. What will be the kinetic energy (in joules) of the mass when its displacement is one-fourth of its amplitude? 2. Relevant equations total energy = KE + PE = .5kA2 KE = .5mv2 PE = .5kx2 3. The attempt at a solution All I have written down is- 1600 J = .5kA2 So, I have no idea how to start solving this problem. Can anyone help me get started? Any help is appreciated!