4) A certain car consists of a 1000 kg body resting on its suspension. The 80 kg driver drops a 200 kg load into the car and observes the car body performs daniped harmonic motion with a period T : Is. He also observes that over one period, the amplitude decreases by a factor of 5. a) Find the damping force constant c and the spring constant k of the suspension. The driver then gets into the car and drives it at constant speed on a bumpy road with bumps described by y = Asin(1r9:/3) where :1: is the horizontal distance in meters and A = 5 cm. b) At which speed in km fh will the car bounce up and down with maximum amplitude? What is this amplitude