Final answer:
Kate moving down the hill has mechanical energy, which encompasses both her potential and kinetic energy as she descends.
Step-by-step explanation:
As Kate is moving down the hill, she possesses mechanical energy. This type of energy is associated with the motion and position of an object. In Kate's case, as she moves down the hill, her potential energy is being converted into kinetic energy, which is the energy of motion. Similar to the example of the boulder rolling down the mountainside where potential energy (PE) is converted to kinetic energy (KE), and some of that energy is further transformed into thermal energy due to friction, Kate's motion down the hill is primarily characterized by a conversion of PE to KE as well. Furthermore, the splashing of a liquid, which resembles oscillation, involves mechanical energy due to the motion and the forces involved.