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
'To myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.'