1. The problem statement, all variables and given/known data Consider an asymmetrical nonlinear spring whose force law is given by F=-kx+(k2)x^2 + (k3)x^3. k=300 k2=300 k3=200 m=2 d=.5 Here's the problem statement as a google doc: http://docs.google.com/Doc?id=d277r7r_54dgf3xhgb&hl=en 2. Relevant equations U=integral (F,dx) 3. The attempt at a solution a. It's called an asymmetrical spring because the force necessary to stretch the spring x units changes depending on how far the spring is from the origin. So basically, graphically, the force by distance graph looks like x^3, which is NOT symmetric about the y axis, thus the spring is asymmeetrical. b. So, for this I thought what I could do was find the potential energy at the original distance of .5 meters. I would do this by integrating Fdx. Thus, U(.5)=16.66666 Now, I find U(.25), which is: U(.25)=6.7708333. Thus, KE=U(.5))-U(.25)=9.896 Thus, 9.896=mv^2/2, and m=2 kg, so I can solve for v using that equation, which would give me: v=3.14157 m/s Is that right?