Question

Describe static and dynamic methods of determining the force constant of a spring.

Answer 1

Method #1 - Static Approach:

Select a series of masses that give a usable range of displacements. The largest mass should not pull the spring past its elastic limit, for two reasons: (1) beyond the elastic limit there is no well-defined spring constant, and (2) a spring stretched beyond the elastic limit will be damaged.

Clamp the metal rod to the table, and hang the spring from the rod. Decide on a procedure that allows you to measure the distance a spring stretches when an object hangs from it in a consistent manner. Decide how many measurements you will need to make a reliable determination of the spring constant.

Method #2 - Dynamic Approach:

Secure the spring to the metal rod and select a mass that gives a regular oscillation without excessive wobbling. The largest mass you choose should not pull the spring past its elastic limit and the smallest mass should be much greater than the mass of the spring. Practice starting the mass in motion smoothly and consistently.

For both methods, make the measurements that you need to determine the spring constant. DO NOT STRETCH THE SPRINGS PAST THEIR ELASTIC LIMIT (ABOUT 60 CM) OR YOU WILL DAMAGE THEM.