A bungee cord stretches 2-4 times their unstretched length, and a jumper feels no more than 2.5-3.5g of acceleration. Assume the force in the cord has the math form k-, where k and are constants and is the amount of stretch in the cord past the unstretched length. Design a cord (design the constants k and ) so the cord stretches 2.5 times the unstretched length, and the acceleration of the jumper doesn't exceed 3g, and the cord has zero stiffness at the bottom of a 400ft drop.