Using PhET simulations, students explore the relationship of kinetic and potential energy in a closed system. Students become aware of the Law of Conservation of Energy and also experiment with friction. The original version of this lab uses the following web page: https://phet.colorado.edu/en/simulation/energy-skate-park-basicsHowever, PhET has created a new and improved version of this sim available here: https://phet.colorado.edu/sims/html/energy-skate-park/latest/energy-skate-park_all.ht