This lab uses a simulation app (ht_tpsz/fphet.colorado.edufsims/html/energy-skate-park/latest/energy-skate-park en.html) to investigate the principle of Conservation of Energy for a skater that moves up and down of a curved ramp. In the absence of non-conservative forces (in this case friction with the ramp and air), the sum of kinetic and potential energies (E : KE + PE) should remain constant during the motion. The app has 4 sections that can be used to explore various aspects related to energy conservation. In all of them, the shape of the ramp can be changed and position, time and speed of the skater can be monitored as the skater moves because of gravity. The friction force can be turned on and off. After familiarizing and playing with the controls, and understanding how the app works, start the experiment in the "Playground" section. The goal is to build a ramp of any shape you want, monitor the position and the speed of the skater and understand how the principle of energy conservation works in this instance. Procedure: In the "Intro" section, start the skater at the top of the ramp. Move the reference height to the starting point and display the energy and the speed. 1. The skater goes down and then back up to the exactly the same reference heigth because ..... 2. The total Energy = KE + PE is equal to ...... 3. What happens to kinetics energy, potential energy and thermal energy when there is friction ? 4. How does the total energy change when there is friction? Explain Start experiment #1 in the "Playground" section by building a ramp by putting together as many ramp sections as you need. Use the ruler widget and the speed dial to record the position and the speed of the skater along the ramp. Start the simulation by placing the skater at some high point. Pause the simulation and record the position and the speed at 8 different position along the ramp. Because of the conservation of mechanical energy we can write the balance between the energy at the starting point and the energy at an arbitrary point along the ramp From this balance equation show that