In the figure, a red car and a green car, identical except for the colour, move toward each other in adjacent lanes and parallel to the xâaxis. At time t=0, the red car is at x r =0, and the green car is at x g =220m. If the red car has a constant velocity of 20km/h, the cars pass each other at x=44.5m, and if it has a constant velocity of 40km/h, they pass each other at x=76.6m. What is the constant acceleration of the green car?