What is the spring constant of the spring

A spring is hung from the ceiling. A 0.600-kg block is then attached to the free end of the spring. When released from rest, the block drops 0.130 m before momentarily coming to rest, after which it moves back upward.

(a) What is the spring constant of the spring?
(b) Find the angular frequency of the block's vibrations.

So the distance between the top of the motion and the bottom of the motion is 0.130 meters. This means that the amplitude of the motion is half that distance (since it is measured from equilibrium position and maximum and minimum height are the same distance from equilibrium) or 0.075 m. You can use the following formula to find k.

mg = kx where m is the mass of the block, g is the magnitude of gravitational acceleration, and x is 0.075 m

Once you know k, you can easily find angular frequency.