A red car and a green car, identical except for the color, 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 = 220 m. If the red car has a constant velocity of +20 km/h, the cars pass each other at x = 43.9 m, and if it has a constant velocity of +40 km/h, they pass each other at x = 77.1 m.
(a) What is the initial velocity of the green car? (Indicate direction with the sign of your answer.)
? m/s
(b) What is the acceleration of the green car? (Indicate direction with the sign of your answer.)
? m/s2