A mass of 0.8 kg is fixed at a vertical spring with an unknown spring constant. When spring is released from rest, it extends to 15cm before it stops. As the system oscillates with Simple Harmonic Motion (SHM) the weight is pulled down 20cm further downward and being released. 1. What is the spring constant?
2. What is the total energy of the system?
3. What is the angular frequency of spring?
4. What is the velocity of the system at x=10cm below equilibrium position? ​

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

Iknow the first part it is the average star i am not 100% sure