The force, F, needed to stretch or compress a spring a distance x (away from its rest position, which is defined to be x = 0) is given by F = k x for some constant k, called the spring constant. The sign of F This is called Hooke’s law. It’s reasonably accurate for a lot of springs

(and even for many elastic bodies), but breaks down if you stretch or compress the spring too much. Interestingly, Hooke first stated this (in 1676) as a Latin anagram. Nowadays scientists don’t state their results as Latin anagrams, and the world is probably the poorer for it.

tells us whether we are stretching or compressing the spring;

here we’re using the convention that a positive force will stretch the spring, while a negative force will compress it.

a. If F has units of N and x has units of m, what are the units of k?

b. How much work is required to compress a spring from x = 0 to x = −2 cm? What is the average force used?

c. How much work is required to extend a spring from x = 0 to x = 2 cm? What is the average force used