Two drivers (driver A and driver B) are traveling in opposite directions on a long, straight road at different constant velocities. Their motions are represented by the position-time graphs of each, shown below. Position (km) 80 60 40 20 0 -20 -40 Position-Time Graph for Two Drivers B A -60 -80 -100 1 Time (h) 2 a. How long had driver A already been driving when driver B started to drive? b. How long had driver A been driving when she was 30 km away from her starting point? c. Which driver is faster? d. What happens at point P?