Aspring whose natural length is 1010 cm exerts a force of 3030 n when stretched to a length of 1515 cm. (note 1515 cm - 1010 cm = 55 cm = .05.05 m ) find the spring constant k=k= 2 determine the work done in stretching the spring 77 cm ( =.07=.07 m) beyond its natural length. w=w= joules

The equation that relates the spring extension to the force applied to it is linear:

where  is the spring constant. 
Hence 
because 
The work done when stretching the spring is

The work is negative because we stretch the spring while the string oposes to this stretching.

Iread this book last year so take this with a grain of salt.gene jumps from the tree to compete with finny due to the fact that gene is always trying to do better than finny. he is put under the grasp of peer pressure due to finny almost forcing him to do this. ever since he first jumped finny kept pressuring him to jump since he thought gene enjoyed jumping.rather than uses this answer you should probably just reread chapters 3-4