 I'm going to give you a really quick tutorial on using Tracker. So I've already got the program opened up here. So what do we do next? You need to find a video too and I'll tell you about how to get videos, but I've already got a video. So I need to import the video and that's the first thing. So I'm going to click video import and then you'll just, you can't see it, but I have a browser, a file browser over here and you select your file, boom. This is a video of Angry Birds. It's a good one to start with because it's pretty easy. So if you want, you can play the video and watch it and stuff like that. And in fact, and you can scroll and this is the first thing that you want to do. I don't, I don't want all this stuff in the beginning. I just want the guy flying. So I'm going to scroll to right. Let's see. I'm going to skip there and this is frame 101. You see that right there. So up here, I'm going to click on the video, the clip settings and it brings this up. So I'm going to start on frame 101. And then that way the program will just ignore the rest of the stuff. In the clip settings, you can also do step size and stuff like that. And the frame rate, you should be okay. Okay. If it's a really high speed video, you might want to do every other frame just because but okay. So now up here, I can do a couple of things. I can click this to show the coordinate system and I can move that. Let's just put it right there for really no reason at all. The next thing I want to do is I have to tell it how big things in the video are. So up here, I'm going to use calibration stick and this has a little stick. I can drag it around. I'm going to make the length of the boomerang, I mean the slingshot, that's the length as one. So I'll just type one. Now that will scale everything in the video. I can move it now. Okay. What next? Well, I think we're ready to go ahead and start marking the motion of this. I'm going to first do it manually to see how you do that. So here I'm going to go to create a point mass. And then it's called mass A. Now, if I hold down the shift key, see, if I hold down the shift key, it turns into a different little box, you see. And then all I have to do is just click on the Angry Bird and it skips the next frame and I click on the Angry Bird and it skips the next frame and I just keep on doing that. And this can sometimes be tedious, but sometimes it's pretty easy. I'm just going to get enough so I can fit some data here, show you how to do that. You can zoom in and stuff if you want. Go to zoom to fit, it doesn't really matter, but this one is pretty straightforward. What I'm doing is a simple case here. You can see that you want to try to get right in the middle, in the same location each time. Okay. That's good enough. Now over here, you see two windows. This window shows a plot of whatever I want. Right now it's showing X versus T. I can change that to Y and you can see, you can see that. I could change that to X, even if I wanted to. But I want to do Y versus T. And here's the data of that. If you want to export that, you can go to copy and then paste it into a spreadsheet or a text file to use with the Python or whatever. So over here, I'm going to right click on this and go to analyze and it's going to bring up this window. And now I see the same data, but I can fit a function to it, which is really useful. So here I can fit a quadratic function, okay, and see that's what I did right there. And it gives me Y equals A, T squared plus B, T plus C, where these are the values of A, B, and C. So that's pretty useful, okay. I could do the same thing for Y, I mean for the X coordinate, it should be a linear, analyze that. Okay, this shows that last one too, I can turn that off. This is not going to be a problem, but a line and the slope would be the X velocity. Okay. One more thing. Let me add another mass. Let me do the second shot. So I'm going to create a point mass. Now I'm going to have to skip forward to when it's launched, because it starts back at the beginning of the video, okay, right there. And I'm going to go to click on this, and I'm going to show you something awesome called auto track. And it says, there's a little dialog box comes up, click on what you want to track, click. You can change a whole bunch of things here, I'm just going to do really quick offset origin next, except scores above next. Look ahead, search. Look at that. It's doing it automatically. Okay. And I'm going to pause it, pause and close. So now I have that data too. Look at that. Awesome. Okay. That's it for a quick super intro. There's a lot of other cool things to learn, but that's as quick as I can get.