Online Simulation Lab \( \rightarrow \) ROLLER COASTER PHYSICS Purpose, The purpose of this simulation lab is to strengthen your understanding of energy conservation in real-world applications. You will use a skateboarder and his park to represent the roller coaster and Qus bel its track. You will observe many other physics concepts at work as well. Open up the University of Colorado, PhET Energy Skate Park simulation: exl 1. Go to http://phet.colorado.edu/ 2. Click "Play with Sims ...>" 3. Click the "Energy Skate Park" icon 4. Click "Run Nowl" 5. Spend ONE MINUTE to explore the simulation and familiarize yourself with the controls. 6. Click the "Reset" button in the top-right corner. Begin the exploration below. Exploration Questions Use the simulation to answer the questions below. 1. Does the skater hit the same height on the opposite sides of the track? (Checkmark the "Show Grid" button to help you determine thisl) a. What must be true about the system for this to be possible? b. Click the "Track Friction \( \gg \) " button to adjust the friction settings. What do you observe about the skater as you adjust the setting? 2. Now, turn on the energy Pie Chart and Bar Graph. (You may need to move things around a little to see everything.) a. On the visual aids, what color represents potential energy and which is kinetic energy? b. When does the skater have the highest amount of kinetic energy? Potential energy? c. When does the skater have the lowest amount of kinetic energy? Potential energy? d. Describe how the bar graph changes as the skater moves along the track. e. Explain which visual aid (pie chart or bar graph) helps you understand conservation of energy better, and why. f. Keep your preferred visual aid open for the remainder of the investigation.

To answer the exploration questions based on the Energy Skate Park simulation, let's break down each question step by step. ### 1. Does the skater hit the same height on the opposite sides of the track? - **Observation**: When you run the simulation and observe the skater moving along the track, you will notice that if there is no energy loss due to friction, the skater reaches the same height on both sides of the track. #### a. What must be true about the system for this to be possible? - **Answer**: For the skater to hit the same height on both sides of the track, the system must be closed and isolated, meaning there is no energy loss due to friction or air resistance. The total mechanical energy (potential + kinetic) must remain constant throughout the motion. #### b. Click the "Track Friction \( \gg \) " button to adjust the friction settings. What do you observe about the skater as you adjust the setting? - **Observation**: As you increase the friction, the skater will not reach the same height on the opposite side of the track. The skater loses energy due to friction, which converts mechanical energy into thermal energy, resulting in a lower height on the return side. ### 2. Now, turn on the energy Pie Chart and Bar Graph. #### a. On the visual aids, what color represents potential energy and which is kinetic energy? - **Answer**: In the simulation, potential energy is typically represented by the color **blue**, while kinetic energy is represented by the color **green**. #### b. When does the skater have the highest amount of kinetic energy? Potential energy? - **Answer**: - The skater has the highest amount of **kinetic energy** at the lowest points of the track, where the speed is greatest. - The skater has the highest amount of **potential energy** at the highest points of the track, where the speed is lowest. #### c. When does the skater have the lowest amount of kinetic energy? Potential energy? - **Answer**: - The skater has the lowest amount of **kinetic energy** at the highest points of the track, where the speed is minimal or zero. - The skater has the lowest amount of **potential energy** at the lowest points of the track, where the height is minimal. #### d. Describe how the bar graph changes as the skater moves along the track. - **Answer**: The bar graph fluctuates as the skater moves along the track. When the skater ascends, the potential energy bar increases while the kinetic energy bar decreases. Conversely, when the skater descends, the kinetic energy bar increases while the potential energy bar decreases. The total height of the bars combined remains constant if there is no energy loss. #### e. Explain which visual aid (pie chart or bar graph) helps you understand conservation of energy better, and why. - **Answer**: The **bar graph** may help understand conservation of energy better because it provides a clear visual representation of how kinetic and potential energy change relative to each other as the skater moves along the track. It allows for easy comparison of energy types at different points in the motion. #### f. Keep your preferred visual aid open for the remainder of the investigation. - **Action**: Keep the bar graph open to continue observing the changes in kinetic and potential energy as you manipulate the skater's motion and track settings. ### Conclusion Through this exploration, you can observe the principles of energy conservation in action, understanding how potential and kinetic energy interchange as the skater moves along the track, and how external factors like friction can affect the system's energy dynamics.