APS Excellence in Physics Education Award
November 2019 Science SPORE Prize
November 2011 The Open Source Physics Project is supported by NSF DUE-0442581.

## Roller Coaster Model Applet Page

### Roller Coaster Mechanical Energy

A roller coaster traveling on a track under the influence of gravity. Bar graphs show the potential energy (PE), kinetic energy (KE) and total mechanical energy(E) of the car. You can drag the blue points on the track to new positions to change the shape of the track.

1. Play the simulation and watch what happens to the bar graphs. When is the kinetic energy (green) bar the maximum? When is the potential energy (purple) bar the maximum? How does the total energy (E) bar change? Does its height change? Explain.
2. Stop the simulation. Use the "Steps the Simulation" button to step the simulation. Sketch the bar graph and position of car on the track to show maximum gravitational potential energy. Do the same to show maximum kinetic energy.
3. Place the cross hairs on the car to find the height. Record the height and velocity of the cart at the maximum potential energy and maximum kinetic energy. Assume the car's mass is 1 kg. Calculate PE when velocity is zero. Calculate KE when height is zero. Do your answers make sense? Why?
4. Select a new track from the drop down menu. Sketch the car on the track at various positions and use the heights of the graphs to show that mechanical energy is conserved.
5. Advanced: Try the simulation where you add friction (click the Friction checkbox). What happens to the energy bar graphs? Why? Form a hypothesis about when mechanical energy is conserved.
Additional information on this applet can be found in the Open Source Physics comPADRE collection.
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