\[T_b\]
of a bnody decrease is proportional to the temperature difference between the body and its surroundings \[T_s\]
.\[\frac{dT_b}{dt}=-k(T_s -T_b)\]
.If the temperature of the surroundings is higher than the temperature of the body then the temperature of the body Will increase at a rate
\[\frac{dT_b}{dt}=k(T_s -T_b)\]
.Integration of the first equation with initial temperature
\[T_0\]
gives \[T_b (t) = T_s - e^{-kt}(T_s-T_b)\]
/ This is an exponential decay curve.