The graph below shows the velocity vs. time for a car that starts its engine at a stop sign. A. What is the average velocity for the first 6 seconds in m/s? B. What is the acceleration for the first 6 seconds in m/s?? C. What is the instantaneous velocity at t=9 seconds in m/s? D. What is the acceleration between 6 and 13 seconds in m/s2?