Final answer:
The top of the mirror must be at least 0.35 m below the level of the eyes to see the reflection of the belt buckle, following the Law of Reflection.
Step-by-step explanation:
The question asks about the vertical location of the mirror relative to the level of the eyes when a person sees the reflection of their belt buckle, which is positioned 0.70 m below their eyes. This problem relies on the Law of Reflection which states that the angle of incidence equals the angle of reflection. When the person sees the belt buckle in the mirror, the path that the light takes from the buckle to the eyes is symmetrical, meaning that the mirror's effective height for this reflection is at the halfway point between the eyes and the buckle.
To determine the vertical location of the mirror, we need to find the midpoint between the eyes and the belt buckle. Since the belt buckle is 0.70 m below the eyes, the halfway point is 0.35 m below the eye level. Therefore, the top of the mirror must be at least 0.35 m below the level of the eyes to see the reflection of the belt buckle.