CGPET 2012 Solved Paper

Newton's law of cooling is a special case of Stefan's law.
Stefan's law "The energy of thermal radiation emitted per unit time by a black body of surface area
A is given by u=σAT4"
and from this equation Newton derived
‌

dT

dt

=−bA(T−T0)‌‌(T=‌ temperature ‌)
or ‌‌‌

dθ

dt

=−k(θ−θ0)