Final answer:
A polished metal surface reflects better because it is smoother, which complies with the Law of Reflection producing a clear reflection, whereas a rough surface scatters light and creates a diffused, less distinct image.
Step-by-step explanation:
You can see your reflection better in a piece of metal if you polish the surface because polishing makes the surface smoother. The Law of Reflection states that when light rays strike a smooth surface, they reflect at equal angles relative to the perpendicular to that surface, allowing for a clear and sharp image. If the surface is rough, the light rays scatter in many directions due to the uneven surface angles, leading to a diffused reflection and a less distinct image. This is why polishing a mirror with sandpaper is not recommended, as sandpaper creates scratches, which in turn make the surface rougher and degrade the quality of the reflection.