A sphere is at temperature 600 K . In an external environment of 200 K , its cooling rate is ' R '. When the temperature of the sphere falls to 400 K , then cooling rate ' R ' will become

Step-by-step solution

The rate energy emission from a hot surface is given by Stefan-Boltzmann Law. R = e A ( ~T ^4- T ₀^4 ) Hence, R ^ R = (400^4-200^4 ) (600^4-200^4 ) = (256-16) 10^8 (1296-16) 10^8 = 3 16 R ^ = 3 16 R