Describe how energy changes forms as a skateboarder goes from the top of a U shaped ramp to the other side at the top. Why don't they continue moving forever?
As a skateboarder goes from the top of a U-shaped ramp to the other side, there are various energy transformations occurring. Initially, the skateboarder possesses gravitational potential energy at the highest point of the ramp due to their elevation above the ground. This potential energy is converted into kinetic energy as the skateboarder starts descending downwards.
As the skateboarder moves downwards, the gravitational potential energy decreases, and the kinetic energy increases. At the bottom of the ramp, when the skateboarder reaches the same elevation as the starting point, the gravitational potential energy is zero, and the kinetic energy is at its maximum.
However, the skateboarder does not continue moving forever due to the presence of external forces that act on the skateboarder and oppose the motion. These forces include friction, air resistance, and the deformation of the skateboard wheels. These forces act to reduce the kinetic energy and bring the skateboarder to a stop.
Friction between the skateboard wheels and the ground converts some of the kinetic energy into thermal energy, causing the wheels to slow down. Air resistance also plays a role, especially at higher speeds, and converts some kinetic energy into thermal energy due to friction between the skateboarder and the surrounding air. Additionally, the deformation of the skateboard wheels as they roll over uneven surfaces results in the conversion of some kinetic energy into other forms, such as sound energy.
Eventually, due to these external forces, the kinetic energy of the skateboarder decreases to zero, resulting in the skateboarder coming to a stop. Thus, the energy transformations from potential energy to kinetic energy are limited by the presence of external forces that dissipate the energy into various forms and prevent the skateboarder from continuing to move forever.