When a certain spring is expanded 6 centimeters from its natural position and held fixed, the force necessary to hold it is 1200 dynes. Find the work W required to stretch the spring an additional 6 centimeters

The force on a spring isF = k (d1 - d0) we say d0=0 and d1 is 6 cm so 1200 = k * 6200 = k

F = k (d1 - d0) where d1 is 12 cm and d0 is 6 cmF to stretch additional 6 cm is 200 * 6F = 1200where work is F * change in distancewe changed the distance by 6 cm so it should be 1200 * 6 = 7200