00:01
In this prime, you're given two motion diagrams.
00:04
First one here, where you, in one second intervals, you travel the same, you have the same displacement.
00:13
Same displacement, as best i could.
00:15
This may be a little bit long.
00:16
Now, what type of curve do you get to, what type of curve represents that? well, that will be a straight line.
00:26
Because if you look at any same time interval, the change in d is the same.
00:49
And that's only going to be with a straight line.
00:53
Now, from the standpoint of the velocity graph, you can look at this two ways.
00:59
First, from a physical standpoint, when you're going the same distance and the same time, by definition that means you must have the same velocity.
01:08
So this must be a horizontal line.
01:14
Otherwise, in one second, how can you travel the same if your velocity is changing? not possible.
01:20
So you could actually see that just from looking at the diagram.
01:23
Now, how can you see that from the graph? if you're asked in general, how from the graph do you get that? well, the answer is the following.
01:32
You, at any point, say here, you draw a tangent line.
01:38
Draw a tangent line.
01:39
And you ask, what is the slope of that tangent line? that is your velocity at that point.
01:45
And you do it at another point.
01:51
And there's your velocity at that point.
01:52
Now, with a straight line, all of those tangent lines have the same slope, which means your velocity graph will be horizontal.
02:02
That's how you do it in general, graphically.
02:05
But obviously, we already can see it from the physics.
02:08
Now, the acceleration, again, just looking at the physics, the velocity is not changing.
02:16
So that means acceleration by definition, the zero.
02:22
Now, how do you do that graphically? same exact thing as you did to get from displacement to velocity.
02:33
You draw tangent lines at points, and those, the tangent lines in each of the points forms your graph, your acceleration graph.
02:49
Well, horizontal tangent line, zero slope.
02:54
They're all zero.
02:55
So, physics leads you, physics leads you to these graphs, but also you have to understand, just in general, just from a graphical standpoint, how you go from one to the other.
03:08
Slopes of tangent line on d versus t, that gives you v versus t.
03:14
Likewise, slopes on tangent line at v versus t gives you a versus t.
03:18
That's how it works.
03:20
That's how it works.
03:23
Now, the second motion diagram, you can see the displacement is getting less between the in the same interval...