The spring-flex exercise system consists of a spring with one end fixed and a handle on the other end. The idea is that you exercise your muscles by stretching the spring from its natural length, which is 34 cm. If a 120 Newton force is required to keep the spring stretched to a length of 54 cm, how much work is required to stretch it from 49 cm to 61 cm? Your answer must include the correct units. Work =