If an object on a horizontal frictionless surface is attached to a spring, displaced, and then released, it will oscillate. If it is displaced a distance 0.110 m from its equilibrium position and released with zero initial speed. Then after a time 0.815 s its displacement is found to be a distance 0.110 m on the opposite side, and it has passed the equilibrium position once during this interval. Find (a) the amplitude; (b) the period; (c) the frequency.