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RE: exponential law of cooling



Hi Ludwik-
No mistake. Proportional to t for short times. You write:
*******************************************************
Let me try. I assume that initially t=0 and T=T_i. If T>>T_0 then
dT/dt=-k*T^4 or dT/(T^4)=-k*dt. I integrate and get

(1/T_i^3 - 1/T^3) = -3*k*t or 1/T^3 = (1/T_i^3 + 3kt)
****************************************************
So solve for T to get:
T = T_i(1+3ktT_i^3)^-1/3
For sufficiently short times this is well-approximated by
T = T_i(1 - 3ktT_i^3),
which is a decrease proportional to t.

Regards,
Jack