When a video is being shot at such close distance to the objects of interest, one thing that has to be taken into note is parallax error. Now we can have a look over at the preview window here. We can see the angle of the air track side is that direction and the angle of it on the other side is pointing the other direction. Now because of parallax error, this usually means that any measurements towards the center of the image are more accurate than those towards the edges. So after these cuts on the air track collide, I'm going to measure from what's closest to the center. So I'm going to measure from the back part of this card. So we can already see that the distance that we're measuring now is smaller than what it was before. Now just do a couple more points to get a reasonable comparison to. And then we'll start the analysis. And that should do the trick. So we'll turn the show edges off and zoom out again to see how we did. So that's looking fairly reasonable. So we just play it through. There's our collision. Our results are looking very good. Okay. Now another feature with this version of Fizmo is the take snapshot button. So with this happening here, we just click the take snapshot button. And it will save a copy of the image in the working directory that we're in. So if we go into that directory, here it is here with all the marks on it, which can be used in a report for students. Now we'll save a copy of the file here to analyze. We'll pull this one and track data. Save. And we can open this. Track data. So I'm using Libra Office, which is an alternative to Microsoft Office for those that don't have the Microsoft Office installed on their system. But this is an XLS file. It'll work well in either of those two programs. So we now calculate the difference in the displacements on X. So this will be equal to that. Subtract. And we get a series of data like so. And then this is the post collision displacements, which we get as our results. Now we can get an average of those before it, which is that. And then we can get an average of them afterwards. We're getting this. And this is equal to the percentage of that divided by that times 100, giving us 49.16%. So this is telling us that two carts of equal mass, once they combine, have essentially half of the velocity of the original cart. And theoretically, this is what should be occurring. Of course, differences here could be due to the measurement on screen, or it could also be due to losses in the system itself. If we go back to the original video. And play it at lower speed. We can note that the original collision itself, if you watch here, is not as efficient as it could potentially be. And so this isn't potential reason why we didn't get bang on 50%. But that's for students to calculate and work out for themselves. And this provides a good, a relatively good discussion point to be brought up in class. Thank you very much. I hope you enjoy the new version of his mode.