2.11 .. A test car travels in a Figure E2.11 straight line along the x-axis. The x (m) graph in Fig. E2.11 shows the car's C 40 B position x as a function of time. 30 D Find its instantaneous velocity at 20 points A through G. 10 E 0 1 2 3 4 5 6 7 8/9 10 F G t (s)