Thanks guys. What I am looking for is the formula to convert the area underneath the force draw curve into a useable number for ft-lbs of stored energy (SE), so I can compare my arrow's KE to my bow's SE in order to measure the bow's efficiency using different weight arrows...trust me, I do not get this technical for my everyday shooting...I just need to get through this science project. Again thanks to all who have or may respond...now it is back to the homework!