b. Compare what happens to potential energy, kinetic energy, andtotal energy as the skater moves up and down the track. Whatgeneral statement can you make about the relationship betweenpotential and kinetic energy?
c. Notice that the bar entitled “Thermal†energy does notdeviate from zero. This represents an energy that is transformedinto \"heat\" energy. What must be true of this skate park for thisto remain at zero?
d. Vary the skater's Mass with the slider on the right while thesimulation is running. Describe the similarities and differencesthat changing the mass has on the bar graphs.
e. Click on the Friction tab at the bottom and choose theparabola track. Place the skater at the top. Examine the bar graphsas the skater oscillates back and forth. What is happening to theenergies present? Explain how you know that energy is still beingconserved.
f. Run the simulation as in part “e†until the skater comes to astop. What form did the skater’s initial energy end up as?
Use the above graphs to answer the questions below. a. Estimateroughly where was he located at the times listed below:
• zero seconds? ___________________
• 6.8 seconds? __________________
• 8.1 seconds? _________________
• 5.3 seconds? _________________
b. If his maximum height is 4 m (measured from the bottom of thetrack), what is his height at the times below
• zero seconds? ___________________
• 6.8 seconds? __________________
• 8.1 seconds? _________________
• 5.3 seconds? __________________
Examine the kinetic energy curve on the graph above. Given thathis mass was 75kg calculate his speed at the times below using Ek =½mv2 .
Speed at zero seconds: show any work below v0 = ______________m/s
Speed at 6.8 seconds: show any work below v0 = ______________m/s
Speed at 8.1 seconds: show any work below v0 = ______________m/s
Speed at 5.3 seconds: show any work below v0 = ______________m/s
Choose the Friction tab (bottom of screen) and select thehalf-pipe track. Now select on Grid. This will provide a scale foryou to measure heights in meters. You may assume that the mass ofthe default skater is 75kg. Run the simulation and sketch theEnergy vs time graphs below. You know the shapes of these fromabove, you simply need to determine the transition times (period ofmotion). Use a stopwatch to get a rough idea. Be sure to include alegend to represent your different energy curves.
