Ropes utilized in rock climbing are "springy" so they cushion a climber's fall. A particular rope has a force law given by F=-kx +bx^2, where k=223 N/m, b=4.1 N/m^2 and x is the amount of stretch? Discover the potential energy stored in this rope when it's been stretched 2.62m, taking U=0 at x=0.