How is energy conserved when a roller coaster goes down a hill?

As a roller coaster descends a hill, potential energy is converted into kinetic energy. At the top of the hill, the coaster has maximum potential energy due to its height, and as it descends, this energy decreases while its speed increases, reflecting a rise in kinetic energy. Throughout the ride, the total mechanical energy remains constant, assuming negligible friction and air resistance, thereby demonstrating the conservation of energy principle.