As the box slides up a gentle but slightly rough incline until stopping at the top, several energy transformations occur:
- Kinetic energy to gravitational potential energy: Initially, the box possesses kinetic energy due to its motion. As it moves upward, some of this kinetic energy is transformed into gravitational potential energy as the box gains height above the ground.
- Mechanical energy to thermal energy: The roughness of the incline causes friction between the box and the surface. This friction converts some of the mechanical energy (the sum of kinetic and potential energy) into thermal energy due to frictional heating. This energy transformation leads to a decrease in the total mechanical energy of the system.
At the top of the incline, when the box stops, it has converted most of its initial kinetic energy into gravitational potential energy, with some energy lost to thermal energy due to friction. The system now has less mechanical energy than at the start of the motion.
