Suppose a spring has a relaxed length of 25.1 cm. The simulation refers to this as the natural length. This is the length of the spring when it is not stretched nor compressed by any force. When you hang a mass of 250 g on the vertical spring, the spring stretches to a new length of 33.9 cm. What is an estimate of the spring constant, k, of the spring? (Enter your answer in N/m.) Measuring only one value is not a good way to get the value, but you can an idea of the approximate size.

No it doesnt because it can be any number.

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.