A simple harmonic oscillator consists of a block of mass 4.10 kg attached to a spring of spring constant 300 N/m. When t = 0.820 s, the position and velocity of the block are x = 0.188 m and v = 3.670 m/s. (a) What is the amplitude of the oscillations? What were the (b) position and (c) velocity of the block at t = 0 s?