Before Oaks Park

Before Oaks Park:  

(This is an individual lab - every person needs to do their very own analysis)

Part 1 - Phyphox Basics

1. Download the phyphox app to your smartphone.  (If you can't, borrow someone else's phone to get your data, and email it to yourself)

2. Run the app, and under Raw Sensors choose either Acceleration (without g) to ignore gravity, or Acceleration with g (Which I prefer personally).  If it is in "Acceleration with g" mode, and you hold the screen vertically, the y axis will read 9.8 m/s/s, and the “without” mode will ignore gravity and read 0.0 m/s/s.  Try both and decide which makes the most sense to you.  <Video>

3. Hold the phone with the screen vertical.  Try accelerating in each of the three directions indicated by the diagram.  Practice interpreting the graph you see on the screen.  The x and y axes are intuitive to me, but the z axis seems backwards a bit.  Spend some quality time with this now, don't just rush on to the next step.  You need to know what these directions mean, and how to make the different accelerometers register both positive and negative bumps.  

4. Press "Pause" when you are done collecting data, either hit "Trash" to get rid of the data, or hit the three dots at the top right, and choose "Export Data".  The most straightforward format to export to Google Drive is “Excel” IMO.  On iOS, you can "Save to Files" and choose Chrome.  <Video> This will put it in your downloads folder.  When you later have good Wifi, you can go into Chrome downloads, and email the data to yourself.  There are other ways to do this as well, find a way that works for you. <Video>

Part 1:  Holding the phone with the screen vertical (as in the above diagram), make and export three separate screenshots, one for an 

• acceleration in the x-direction (move phone to the right, pause, and then to the left), one for an 

• acceleration in the y-direction (move the phone vertically upward, pause, then vertically downward), and one for an 

• acceleration in the z-direction. (move the phone toward you, pause, and then away from you).   

To do this, click on the particular graph you are doing like x, y or z, (To make that graph take up the whole screen)  hit the "Play" button to record data, move the phone as instructed, and then when you are done, either just screenshot your phone, or hit the three dots and choose "Share screenshot".  Put these screenshots on the first slide.  Check out this example.

Please follow the directions - don't just submit random graphs.  Make sure your graphs look more or less like the example below:

Part 2 - Exporting Data and Graphing

Make one of the graphs above (not just something random) using Phyphox, , save the data to your phone, and export it to Google Sheets.  (See the videos in step 4 above)  Delete the non relevant columns in Google Sheets, make an x-y scatter graph with a smooth line through it.  <Video>   Check out this example.  

Part 3 - Vernier Video Analysis

1. Download this movie to your drive or your device: SmallFrogHopper14.mp4.

2. Go to the Distance Reference on the Main Oaks Park Page for the Frog Hopper: " | Ferris Wheel | Frog Hopper | Go Karts | " and write down the distance across the bench right above the eyes.  (I tell you what it is below the photo with the big red arrow - it's between 2 and 3 meters - scroll down a bit - you'll see it)  <Video Steps 1 and 2>

3. Run the Vernier Video Analysis App by clicking on the "Video Analysis Key " link then clicking on the Key (a bunch of characters) and then the link it brings up Google Docs style.

4. In the App, click "CHOOSE FILE" and find the movie you just saved.  (SmallFrogHopper14.mp4) in step 1.

5. On the left side, click "SYSTEM" and drag the ends of the distance reference across the bench above the eyes right where the red arrow was.  Type the distance you looked up in step 2 into the dialog box at the top.

6. Hit the "Play" button, and watch the movie.  Notice it starts with an immediate "Frog Hopping" event, and then the operator raises them up and does one more, and then the movie is over.  This is the kind of short movie you want to capture at Oaks Park - you want to capture a short movie of the motion that is causing the "g-force" that the ride is about.

7. Drag the movie window tab to make the movie frame as big as possible on the screen.  Go back to the beginning of either the entire movie, or the beginning of the second "Frog Hopping" event.

8. Click the Gear icon in the lower right and choose to gather data every 2 frames.  <Video Steps 3-8>

9. In the upper left, click the "ADD" crosshairs, but don't click on the movie yet.  Now, every time you click within the frame, the software will record the position of the click in x and y coordinates in the data table.  Now, if you use the center of the crosshairs to click, it will leave a blue dot there, which makes it hard to see where to click, so I use the left side of the crosshairs to click on one of the eyeballs. 

10. Try clicking on the movie, and track either the top edge of the ride, or one of the sets of frog eyes down, then up then down then up then down.  (The entire "Frog Hopping" event!)  It's a lot of clicking.  <Video Steps 9-10>  <Hack>

11. Now make the graph as big as you can.  Click on the left side of the graph where it says x and y, and choose just the y data.  Pick an upwardly concave section of the graph (upward acceleration), select it, and click the curve fit button on the lower left of the graph, and select "Apply Curve Fit" and then a quadratic model.  Click "APPLY" and see the formula for the curve fit.  The coefficient "a:" is exactly half the linear acceleration, so if it says for example that a: is 3.123, then your acceleration is 6.246 m/s/s (twice 3.123)   (because distance = 1/2at^2)  Screen shot your analysis into the second slide of your slide show.  Make a text box where you show your calculation of the acceleration (Twice the coefficient "a:" in the model you created)  <Video Step 11>

12. Do the same thing for a downwardly concave section of the graph. (downward acceleration)  <Video Step 12>

Check out this example. 

As a Group: (once you have your rides)

1. Create a shared slide show that you each have editing access to.  When you have your rides assigned, create slides and research the rides.  Find some interesting information about each ride, and put a bullet point for these on your slide.  Put the information on a note card.  (So you are not reading words off your slide)

2. Decide what data and what analysis you want to do with the ride.  Make a data table for each ride, and make a game plan.  Decide who is getting what data.  My suggestion is to gather every piece of data you can.  If it rotates, time the period.  If it swings time the period.  

3. Go to the main page, and write down all the measurements we have for each ride.  Write down the formulas you will use to calculate quantities.