Describe Leslie’s-cube comparison, controlled variables, observation and conclusion.

Solution & explanation

Fill a cube with hot water so its different faces are at approximately the same temperature. Aim the same radiation detector at equal distances and comparable areas of each face, avoiding reflections and detector drift. Compare readings: the dull black face is generally the strongest emitter in the school setup and polished metal weaker. Equal temperature, geometry and detector settings are essential; otherwise the surface effect is confounded.