The velocity of a bacterium undergoing one- dimensional motion is shown as a function of time in the graph to the right. A. Over which time interval(s) is the bacterium: 1. speeding up? 2. slowing down? 3. moving at constant speed? Velocity (um/s) C. What is the acceleration of the bacterium at t = 2 s? 20 10 O -10 -20 B. What is the total displacement of the bacterium between 0 and 20 s? Don't forget to specify its sign. 20 Time (s) D. What is the average acceleration of the bacterium from t=0 stot = 9 s?