The graph in the accompanying figure shows the magnitude of the force exerted by a given spring as a function of the distance x the spring is stretched.

Part A How much work is needed to stretch this spring a distance of 2.00 cm , starting with it unstretched.

Part B How much work is needed to stretch this spring from x1 = 5.00 cm to x2 = 7.00 cm ?
 

F (N) 350 300 250 200 150 100 50 1 2 3 4 5 6 7 8 x (cm)