In the figure here, a red car and a green car move toward each other in adjacent lanes and parallel to an x axis. At time t = 0, the red car is at xr = 0 and the green car is at xg = 218 m. If the red car has a constant velocity of 27.0 km/h, the cars pass each other at x = 44.3 m. On the other hand, if the red car has a constant velocity of 54.0 km/h, they pass each other at x = 76.6 m. What are (a) the initial velocity and (b) the (constant) acceleration of the green car? Include the signs.