Will a black container of hot water lose heat faster or slower than a white container of hot water?
Asked by: Katy Ward
Answer
A black body is assumed to be a perfect radiator of heat.
A black container of water can be said to be closer to a black body than a white container. Kirchoff's laws of radiation make it evident that a BLACK BODY IS NOT ONLY A PERFECT ABSORBER BUT ALSO A PERFECT emitter of heat. Hence the black container will cool down faster.
Wear a black cotton shirt in summer, you'll sweat!
Wear a cotton (black) shirt in winter you'll freeze!
Answered by: Akhilesh, Undergrad, India
'One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day.'