How much faster dose a cup of tea cool by `1^(@)C` when at 373 K than when at 303 K. Consider the tea as a black body. Take the temperature as 293 K and Sreafan's constant as `5.7xx10^(-8) Wm^(-2) K^(-4)`.

Answer

`[11.3]`

Explanation

`(P_(1))/(P_(2)) =(sigma A(T_(1)^(4)-T_(0)^(4)))/(sigma A(T_(2)^(4)-T_(0)^(4)))`
`=(T_(1)^(4)-T_(0)^(4))/(T_(2)^(4)-T_(0)^(4))= ((373)^(4)-(293)^(4))/((303)^(4)-(293)^(4))= 11.3`