PURPOSE: To illustrate radiation from various surfaces.

DESCRIPTION: When the cube is heated with boiling water poured into the funnel to fill the cube, each of the six sides of the cube radiates at the same temperature. The amount of radiation emanating from each side is only a function of its surface. Surfaces include (in order of radiative efficiency): black fabric, gray "fabric," white paint, polished stainless steel, flat aluminum, and polished brass.

SUGGESTIONS:

REFERENCES: (PIRA 4B40.30) See Demonstration Reference File for details regarding this apparatus.

EQUIPMENT: Leslie's cube with funnel filling setup, thermopile with DVM, boiling water with hot plate, gloves to handle hot water beaker.

SETUP TIME: 10 min.