Final answer:
The statement is true as the cyclist's potential energy is partially converted into heat due to friction, causing the bicycle to stop at a lower point than where it started.
Step-by-step explanation:
Your question regards the conversion of potential energy into heat energy as a cyclist coasts down one hill and up another. This scenario illustrates a principle in physics known as the conservation of energy, which states that energy cannot be created or destroyed, but can change forms. When the cyclist coasts downhill, potential energy is converted into kinetic energy. As the cyclist goes uphill, the kinetic energy is converted back into potential energy until the bike comes to a stop. However, not all the kinetic energy is converted into potential energy as some of it is indeed turned into heat energy due to friction, primarily between the bike's tires and the road surface.
This is why the tires may become warm and why the bicycle stops at a point lower than where it started, because some of the original potential energy has been lost as heat.