PASCO Capstone Playback, Movie Synching, and Calculations


Hi. My name is Andy Spoone. In this video we’re going to take a look at PASCO Capstone software and the 850 Universal Interface. We’re going to be analyzing the motion of a cart as it goes up and down a track. We’re going to be looking at how to sync that position data with some movie data collected from our webcam. Then we’re going to calculate energy based on the cart moving up and down the track. Let’s begin by creating a full-screen graph. I’m going to double-select Graph display and select Position as my measurement. I’m now ready to start recording data. I’m going to bring the cart out about 15 cm away from the sensor, push it up the track, and then catch it as it comes back down. After we stop recording data, we can scale it. As you can see, we have a nice smooth curve showing the cart going up and then coming back down the track. Now let’s look at how we can play back this data. I’m going to select the Playback mode button and press Play. As you can see, it will play back our data in real time. Now if I want to select a faster or slower rate that I’m playing my data back, I can select the playback speed button and choose an option that’s faster or slower. As you can see, this will slow down your data being played back to you. Let’s go ahead and pause that and create a new page, where we’re going to create our movie sync data. So let’s begin by selecting the Movie display. I’m going to choose Record Movie with Synced Data. You should see a live image come up. So you’re seeing a webcam preview of what’s going to be recorded. Beside that I’m going to put a graph also selecting Position. Run #1 is currently displayed on my graph, but as soon as I start recording again Run #2 will take its spot. So what’s going to happen now when I hit Record, I’m going to get my Run #2 data, but I’m also going to get a movie synced automatically beside it. So let’s go ahead and begin recording. We’re going to stop recording and scale our data. Now we’re going to go back and play it back through the same method we did on page number one. So I’ll select the Play button. This time you’ll see that the data is now automatically synced to our movie. Now let’s take a look at how we can manually adjust those sync settings. I’m going to begin by using my slider and my playback mode to control where my data is. So I’m going to slide my data back to a point that’s easily identifiable in the movie. In this one I’m going to choose my maximum position because that’s where the cart should be at the top of the track. Inside of my movie toolbar I’m going to select the Sync Video button and unchain it. Now I can manually adjust the slider for the movie and move it exactly to where the cart is at the top of the track. I can re-link the data. And now select the red button to finalize your syncing. Now when we go back and rewind and play our data back, you’ll see that the data synced with our fresh new manual synching. In our next step we’re going to go and create some calculations of energy based on this data. So let’s go and open up our Calculator in the Tools palette and click inside of our first calculation line. We’re going to begin by making potential energy, which equals mass times gravity times height. We’re going to give it the units of Joules. As you can see, Capstone has an automatic library of units that you can choose from. Our mass is 250 g, or 0.25 kg. For gravity I’m going to insert a constant from the built-in library. So I’m going to go into Insert Data, choose Constants, and select Acceleration Due to Gravity. And for the height, I’m going to create a new calculation nested inside of my potential energy calculation. So the height is a function of position, which I can choose from my data selection button. And it’s a function of angle, which I can get from my angle indicator at the end of my track. I have an angle of seven degrees. So I’m going to multiply this times the sine of seven, and give it units of meters. I need to remember to go back and change my height so that it is in degrees. It defaults to radians. I’m going to change my position of my graph to PE. After rescaling, you see a graph that’s very similar to position. You see it going up and down. In my next line of the calculator I’m going to create a calculation for kinetic energy, KE. This equals one-half times mass times velocity squared. I’m going to choose Velocity again from my data selector. I’m going to choose squared with my calculator buttons, also having units of Joules. To graph kinetic energy, I’m going to insert a new Plot Area and choose kinetic energy. Now after scaling, you see that the shape of the kinetic energy is inverted to the potential energy. So as the potential energy was increasing, the kinetic energy was decreasing. Now for my final calculation, I’m going to make one for total energy, TE. And it’s going to equal the sum of PE plus KE. I’m going to create one more Plot Area for total energy. So let’s go ahead and scale our data. Then I’m going to go ahead and turn off my legends. Notice we can also give our graphs titles. So I’m going to call this “Energy of cart moving up and down track”. Let’s go ahead and hide our Calculator. Now we see our full page with our movie and our potential energy, kinetic energy and total energy. This time we’re going to go and play back again and see what happens playing back the movie with our new calculations. As you can see, Capstone has synced those new calculations with the movie data that we had synced prior to our graph. So everything plays back nicely matched. Notice we also see total energy having a nice flat line while my cart’s moving up and down the track. This shows that the energy was conserved even though the potential energy and kinetic energy changed as the cart moved up and down the track. I hope you’ve enjoyed our video showing you you can play back your measurement data, sync your measurements with movies, and also create calculations based on your data. Thanks for joining us.

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