G Energy Park

You and a partner may turn in one sheet of paper with the answers to questions A-E

Go the the PhET->Physics->Work and Energy:

https://phet.colorado.edu/en/simulations/category/physics/work-energy-and-power

and run the "Energy Skate Park Basics" (The HTML 5 version)

1. Try the Intro - you will see three different tracks.

Click on the "Speed", "Grid" , and "Bar Graph" check boxes.

For each of these tracks:

1. Drag the skater to a high point on the track, and drop them.

   1. Watch the energy going back and forth between potential and kinetic.

   2. Watch where the speed is the highest, where the speed is the lowest.

A. Where is the skater going the fastest? Where are they going the slowest?

B. What one thing do you need to know to know whether they are going slow or fast? (Their mass?, their height?, their favorite type of ice cream?)

These simulations have no friction in them, so the they are not totally realistic.

2. Now click the Friction Icon at the bottom of the screen. Click the "Bar Graph" Checkbox, make sure that the friction slider is in the middle. (So there is a normal amount of friction)

Put the skater on a high point, drop them, and watch the energy loss due to friction as they oscillate back and forth.

C. As the skater loses KE+PE, where does the energy go? (Look at the bar graph at the end when the skater has stopped moving because of friction)

D. At what part of the track does the skater lose KE+PE the fastest?

3. Now click the "Playground" button. On the right below the toolbar click the button to make it possible for the skater to come off the track.

The track sections can be pulled out of the box and hung in space.

Make a track that starts high, descends, and makes the skater go in an inverted loop.

Try changing the size of the loop.

E. If you make the loop too big, the skater comes off the track. What must be true for the skater to stay on the track inverted?