00:01
So this problem is just finding the slope of a line to prove velocity and acceleration based on the graph.
00:07
So in the first part, we have a position versus time graph, and it wants us to prove the velocity at 20 seconds.
00:17
So what we have to do is in order to find the velocity, we have to find the slope.
00:23
In order to find the slope of a line, we have to pick two points.
00:27
So let's pick this point and this point.
00:31
This case, it does kind of matter what two points you're going to pick, because you want to pick two points that are close by to the point that you're evaluating.
00:40
We can't pick the very last point and the very beginning point because this doesn't have a steady slope.
00:45
So the closer together these two points are, the more accurate our numbers are going to be.
00:49
Once we find our two points, we find the change in y over the change in x.
00:56
So i have that translated into our equation for velocity over here.
01:00
Change in y is the same as change in position.
01:04
So we do our final position minus initial position...