While designing a shock absorbing bumper for a 5-Mg rail car, the spring used for the bumper follows a nonlinear relationship of F = ks2 where F is the force in Newtons and s is the compression distance in meters. Select the proper value of k so that the max deflection of the spring is 0.2 m when the rail car has a contact velocity of 5 m/s. Ignore the mass of the wheels.