Hooke"s Law: the force required to stretch or compress a spring beyond its natural length is f (x) = kx where k is called the spring constant.

Hooke"s Law: the force required to stretch or compress a spring beyond its natural length is f (x) = kx where k is called the spring constant. Example A force of 10 lb is required to stretch a spring from its natural length of 7 in to 7.5 in. Find the work done in stretching the spring. How much work is done stretching the spring from 7.5 in to 9 in?