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 can be thought of as moving mountains of ice. As they move over the landscape, they cause glacial erosion, which is defined as the carving and shaping of the land beneath a moving glacier. There are two main processes of glacial erosion. Plucking is the erosion and transport of large chunks of rocks that stick to and get picked up by the glacier.