Online Moving Plots Lab

On the complicated steps there are videos that show you how to do the step. Watch those videos.

1. Watch this video of an air track glider coasting from rest down a slight incline. The left side of the airtrack is up on a book, and the aluminum glider floats on a thin cushion of air so there is essentially zero friction.

2. Take a blank sheet of paper, and make a qualitative (no numbers) velocity vs time graph (Label the vertical axis velocity, and the horizontal, time) for this glider. Don't worry about numbers on the axes - just try to get the shape. You know it starts at zero, and at the end it is moving in the positive direction, so it ends above zero. Try to guess what connects those two points. Draw a graph and take a picture of it and put it in the Google Doc you are going to turn in.

3. Draw a picture of what you think the shape of the position vs time graph will be for this glider. This is a bit trickier, so let me give you some clues. You know it just moves to the right. It starts at zero, goes away from zero in the positive direction, but this line is a different shape. On a position graph, the slope is the velocity, so how do you draw a line with a changing slope? In this case the slope starts out zero, and increases. Try to draw that. If you can't, no worries, I just want you to try. Draw a graph and take a picture of it, and put it in the Google Doc you are going to turn in.

Steps 2 and 3:

4. Create a Folder in your Physics class folder? titled "Moving Plots lab" Move the Doc from Canvas into that Folder, and make a new Google Sheets in that folder.

5. Now pick one of these videos to analyze. It doesn't matter which one you pick - Low medium and high refer to the height I raised the airtrack to, so high will accelerate faster than low. Click on the link, and save the file to your Gooooooogle Drive.

High1-720p

Med1-720p

Med2-720p

Low1-720p

Low2-720p

6. Go to this document <Here> and go to the link in the document. This will run the Vernier Video Analysis web App. (You must be signed in to your ttsdstudents.org account)

Steps 5 and 6:

7. Use the Video Analysis App to analyze from the first frame after I release the glider to the last frame before it stops. You will want to skip about 5 frames per click. Copy the data into your Goooooogle Sheets.

8. In your Google Sheets, calculate the instantaneous velocity at every interval and put it in another column. Put your data table and calculations into your Google Doc

9. Make a smooth line Position vs Time graph from the data in Google Sheets, add a tangent line, and screenshot it into your Google Doc. Be sure you have included minor gridlines so that you can read every 0.1 of a second on the horizontal axis, and every 0.05 m on the vertical axis.

Screen shots to clipboard:

• Chromebook: ctl-shift-screenshot (The key above the 6) This brings up a window, then click "copy to clipboard", and paste it into your doc with ctl-v

• Mac: ctl-shift-command 4 - paste with command-v into your doc

• PC: shift-windows-s, paste with ctl-v into your doc

Step 9:

10. Look at your position vs time graph. Answer these three questions:

• Is it the shape you predicted in step 3?

• What is happening to the slope of your graph as time goes on?

• The slope is the velocity. What is happening to the velocity as time goes on? Why does this make sense?

11. Read the (x,y) coordinates of where the tangent line enters and exits the plot frame and use these to calculate the slope. Show what points you used, and your calculations of the slope. Figure out the time that your tangent line touches the position graph, and write a sentence comparing the slope of your line to the instantaneous velocity you calculated in step 7.

Steps 10 and 11:

12. Make a nice scatter graph of Velocity vs Time with a best fit line, and screenshot it into your Google Doc. Be sure it has appropriate Gridlines. Calculate the slope using the endpoints. Show your endpoints and your calculation.

13. Look at your Velocity vs Time graph. Answer these two questions:

• Is it the shape you predicted in step 2?

• Is your line more curved, or is it maybe just straight with some experimental error? (The slope is the acceleration of the glider)

Steps 12 and 13:

14. Review your completed document and make sure it has:

• Your Two Predicted Graphs

• Data Table

• Position vs Time Graph

  • Gridlines

  • Tangent Line

  • Answers to the three questions

  • Endpoints/Slope Calculation

  • Comparison of slope to velocity in the data table

• Velocity vs Time graph

  • Gridlines

  • Best Fit Line

  • Endpoints/Slope Calculation

  • Answers to the two questions

Then turn it in. Woo Hoo!