When a car is moving it has kinetic energy. When a car is sitting on top of a hill it has potential energy. By hitting the brakes, that kinetic energy is absorbed by the brake pads via friction and converted into heat energy. The friction of the tires is also what provides for turning.
Glaciers change the surface of the land in several ways. By pushing rocks and gravel along with its encroachment a glacier leaves that material behind when it retreats. Most glaciers have water melting out of them when it gets above freezing. That water erodes the landscape forming streams and rivers.
Glaciers and glacial erosion. A glacier is mass of land ice so large that it flows downhill under its own weight. Glaciers develop in cool, wet areas where at least some of the snow that falls during one winter does not melt or evaporate by the next. Masses of snow and ice typically accumulate at the upper ends of valleys on peaks like Mount Shasta and, when the become thick enough, flow down these valleys as glaciers (Figure 10) .