Final answer:
Kinetic energy is highest at the lowest point of a swing due to the increased speed, while potential energy is lowest at this point because the swing is closest to the ground. Hence, the kinetic energy increases and potential energy decreases during the downward swing.
Step-by-step explanation:
The student is asking about the relationship between kinetic energy and potential energy at different points in an object's motion. For an object in motion, such as a child on a swing, kinetic energy is highest when the object is moving fastest, which occurs at the lowest point of the swing. Conversely, potential energy is highest when the object is at its maximum height in the swing because it has the most capacity to fall. When a child swings downward, kinetic energy increases due to the acceleration from gravity, and potential energy decreases because the child is getting closer to the ground. Therefore, the point at which the child's kinetic energy is increasing and her potential energy is decreasing is when the child swings downward.