A graph of v(t) is shown for a world-class track sprinter in a 100-m race. (See figure below. For each answer, enter a number.) Velocity (m/s) 14 12 10 0 2 + Runner Velocity vs. Time 4 6 Time (s) 8 (a) What is his average velocity (in m/s) for the first 4 s? m/s 10 (b) What is his instantaneous velocity (in m/s) at t = 6 s? m/s (d) What is his time (in s) for the race? S (c) What is his average acceleration (in m/s) between 0 and 4 s? m/s 12