Answer:
a) section c
b) at a constant rate
c) below
A. 3m/s^2
B. 0 m/s^2
C. -3m/s^2
D. 1 m/s^2
Explanation:
a) This graph models the change in velocity of time. Since when the velocity decreases over time, the acceleration is negative. This relationship is modeled in the interval from the 9th to 11th seconds which is section c.
b) If the graph is flat, it means the car is traveling at the same amount of meters per second. This means the car is traveling at a constant rate during section b.
c) During section A, the velocity in second 0 to second 4 increases by 12m/s. So, the acceleration is 3m/s^2. This is identical to finding the slope.
During section B, the velocity does not change at all, so the acceleration(and slope) is 0 m/s^2
During section C, over 2 seconds, from 9 to 11, the velocity goes from 12 m/s to 6 m/s, which is a change of -6 m/s. Therefore, the acceleration is -3m/s^2
During section D, over a span of 4 seconds(11 - 15), the velocity changes from 6 m/s to 10 m/s. That means a change of 4 m/s and the acceleration would be 1 m/s^2.