Okay, so for 11: She is negatively accelerating between 3:05 and 3:06 and between 3:08 and 3:09
When you have a speed vs distance graph, the slope of the graph represents the acceleration, since there is a negative slope there we can say she was negatively accelerating
12. So now all we have to do it look for a line going up or a positive slope:
So: 3:00 to 3:02 , 3:07 to 3:08
13. So, when we are looking for no acceleration we are looking for a straight line, or a line with no slope at all which is between the intervals of:
3:02 to 3:05 , 3:06 to 3:07 and 3:09 to 3:10
Hope this helped, let me know if any of it doesnt make sense.
