A block of mass 0.222 kg is placed on the end of a spring which has a stiffness of 150. N/m. It is pulled down 2.60 cm and released. What is the frequency of oscillation?
What is the period of oscillation?
So let's flip this around. Suppose you know that a spring has a spring constant of 5.00 N/m. When set in motion, a block attached to the spring oscillates with a period of 3.15 s. What is the mass of the block?