Haha i did it.. thanks. Another: A force of 600 N stretches a certain spring a distance of 0.3m . What is the potential energy of the spring when it is stretched a distance of 0.3m ? What is its potential energy when it is compressed a distance of 4.0 m ? I know I am supposed to use the Spring Potential Energy equation (1/2)*k*x^2 but how do I find k? Is it 600N?? I've tried 27 and 600 and those are incrorect.