Calculate the work required to stretch the following springs 0.6 m from their equilibrium positions. Assume Hooke's law is obeyed. a. A spring that required a force of 40 N to be stretched 0.2 m from its equilibrium position. b. A spring that required 50 J of work to be stretched 0.1 m from its equilibrium position. a. Set up the integral that gives the work done in stretching the spring 06 m from its equilibrium position. Use increasing limits of integration. EB) dx (Type exact answers.)