A red car and a green car, identical except for the color, move toward each other in adjacent lanes and parallel to and x axis. At time t=0, the green car is at xg=224 m and the red car is at xr=0. If the red car has a constant velocity of 21km/h, the cars pass each other at x=43.3m, and if it has a constant velocity of 42 km/h, they pass each other at x=76.2 m. What are (a) the initial velocity and (b) the constant acceleration of the green car?