Which of the following bodies will lose its heat at the fastest rate? The bodies have the same surface area and initial temperature.
A. A sphere painted black and dull in appearance B. A cube painted glossy white C. A toroid painted shiny black D. A sphere panted shining red
Correct Answer: A
Explanation
A sphere painted hlack and dull in appearance is a black body, and as a hlick body, it is a perfect absorber and emitter of radiant energy. A black body has an emissivity of 1 . While other hirdies have cmissivity in the range \(0<\) \(\varepsilon<1\) On the ollies hand. a shining or silvered surface is a better retiector of radiant energy.
