00:01
For this problem, we are given the velocity graph of a car accelerating from rest to a speed of 120 kilometers per hour over a period of 30 seconds.
00:09
We are asked then to estimate the distance traveled during this period.
00:14
So what i'll do here is just for a rough estimate, we can see that, let's see here, where are the grid lines? we can see that the grid lines are at every five seconds.
00:26
So i'll use that as my first rough estimate, delta t, so delta t equals 5.
00:32
So we can find the lower estimate by first, i'll just write down, delta t times.
00:39
Then i'll take the, we can see that we are increasing over the whole interval.
00:43
So the lower estimate will be taken, will be given by taking the left hand value for each sub rectangle.
00:52
So, or each portion of the remand sum.
00:55
So we can say that it would be about zero plus about 50 for the next, plus the next would be nearly 80.
01:04
So i'll say that that's about 78.
01:06
The next would be at about nearly 100 since let's see.
01:11
Each one of these grid lines vertically is about 20.
01:13
So i'll say that the next will be at about 95.
01:17
Then the next would be about midway between 100 and 120.
01:23
So at 110, i'll say.
01:24
And then lastly, at almost 120, but not quite.
01:29
Not quite...