A simple harmonic oscillator consists of a block of mass 1.80 kg attached to a spring of spring constant 210 N/m. When t = 1.70 s, the position and velocity of the block are x = 0.139 m and v = 3.550 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?