potential energy is energy that is stored in an object. Can also transfer into others forms of energy. Kinetic energy is energy an object has become of its motion.
When the cart started at the top of the hill it was full Potential Energy.
As the cart started to go down the hill it was gaining speed turning it into (PE/KE) Kinetic Energy. That transition occurred because Kinetic Energy only happens when something gains speed. As the cart hit the valley. (on poster) It was still full of Kinetic Energy. As the cart started moving up the last hill it was transitioning from Kinetic Energy, to Potential Energy, (KE, PE). Which then led to the cart coming to a stop on the second hill as Potential Energy. (PE)
