A block of unknown mass is attached to a spring with a spring constant of 7.50 N/m and undergoes simple harmonic motion with an amplitude of 11.5 cm. When the block is halfway between its equilibrium position and the end point, its speed is measured to be 28.0 cm/s. (a) Calculate the mass of the block. kg (b) Calculate the period of the motion. S c) Calculate the maximum acceleration of the block. m/s2