An oscillator consists of a block attached to a spring (k = 475 N/m). At some time t, the position (measured from the system's equilibrium location), velocity, and acceleration of the block are x = 0.420 m, v = -11.9 m/s, and a = -139 m/s2. a) Calculate the frequency of oscillation. (Hz) b) Calculate the mass of the block. (kg) c) Calculate the amplitude of the motion.(m)