00:01
So we're trying to find average velocity over four different time intervals.
00:06
And we know that velocity is equal to the displacement of x over the displacement of t.
00:17
So in order to solve this problem, we're just going to have to find all of the displacements of distance and the displacements of time for those five different time intervals.
00:27
And to do this, i'm just going to make a table.
00:31
With the first one being the second time, t2, the first column being t1.
00:41
The third column is going to be the displacement of them.
00:46
That's just by subtracting t2 from t1.
00:51
And then we will have y2, y1, and then again the displacement of y, which will be done by taking y2 minus y1.
01:10
And it's y in this case because in the context of our point, problem.
01:15
We have a rock going up in the air, which would be up and down, which is y on the graph.
01:24
So in this problem, v is, can be written as v is equal to the displacement of y or the displacement of t.
01:31
And then now that we have the displacement of y and the displacement of t, the last column will just be solving by dividing the two.
01:39
That would be the philosophy.
01:41
So for the first interval, we're given 2 and 1, then 1 .5 in 1, then 1, and 1, 1 .1 and 1 .01 and 1 .01 and 1.
02:00
And finally 1 .001 and 1.
02:06
So the displacement for all of these would just be by subtracting the left column from the right column.
02:11
And those would give us 1 .5 .1 .1 .01 and point 0 .1.
02:24
And now to find y2, we just plug in the t to into the equation given, that is 10 t minus 1 .86 t squared.
02:37
And this would give 12 .56, 10 .815, 8 .75, 8 .75, 8 .2, 8 .25, 8 .2, and 8 .15.
03:13
And then y1 will be the same thing, but with plugging in 1.
03:17
So all of these are going to be the same as they all have the same t1 value, and that is 8 .14.
03:32
So then to find the displacement of y, we'll just subtract all the y2s from all the y1s.
03:37
This will give 4 .42, 2 .675.
03:51
These values won't match up perfectly if you plug them in using purely what i have here...