What is an example of kinetic energy being transferred to potential energy?

consider a rollercoaster with two hills. after it goes down the first hill, the kinestic energy of the coaster is converted into (gravitational) potential energy as it goes up the 2nd hill

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.