In the equilibrium position, the 30-kg cylinder causes a static deflection of 50 mm in the coiled

Question:

In the equilibrium position, the 30-kg cylinder causes a static deflection of 50 mm in the coiled spring. If the cylinder is depressed an additional 25 mm and released from rest, calculate the resulting natural frequency ƒ_n of vertical vibration of the cylinder in cycles per second (Hz).