Using Hooke's Law, we can show that the work done in compressing a spring a distance of x feet from its at-rest position is W = 1/2kx², where k is a stiffness constant depending on the spring. It can also be shown that the work done by a body in motion before it comes to rest is given by w w̃ = w/2g υ², where w = weight of the object (lb), g = acceleration due to gravity (32.2 ft/sec²), and v = object's velocity (in ft/sec). A parking garage has a spring shock absorber at the end of a ramp to stop runaway cars. The spring has a stiffness constant k = 9450 lb/ft and must be able to stop a 4000-lb car traveling at 25 mph. What is the least compression required of the spring? Express your answer using feet to the nearest tenth. Solve W> w̃, x ≥ 0.