00:04
We're asked to answer a question about finding the average speed using the methods of this section.
00:20
So we're given that the distance s in feet of a moving car from a stoplight is given by the function s of t equals 20 t to the three halves.
00:44
Where t is the time in seconds, we are asked to find the average speed of the car from, time t1 equals 0 to time t2 equals 9.
01:05
Then we're asked to explain why the result is less than the value obtained in part b of example 7.
01:16
Now, the result in part b of example 7 was 76 feet per second.
01:27
First of all, we'll find the average speed of the car from 0 to 9 seconds.
01:34
Well, we have that.
01:39
This is the slope of the second line through the graph of the speed of the car.
01:47
Sorry, this is a slope of the second line through the graph of the distance.
01:53
The car is from the stoplight, and a second line goes through the two points corresponding to t equals zero and t equals nine...