P.S. The answer is NOT 13.4 s, something entirely different.:)
A block of unknown mass is attached to a spring of spring constant 3.3 N/m and undergoes simple harmonic motion with an amplitude of 7.2 cm. When the mass is halfway between its equilibrium position and the endpoint, its speed is measured to be 29.2 cm/s. Calculate the mass of the block. Answer in units of kg.- Find the period of the motion. Answer in units of s.