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ameliusyesterday at 10:06 PM4 repliesview on HN

That model doesn't explain the relatively sharp drop in the beginning.


Replies

spiralcoastertoday at 1:47 AM

It absolutely does. The model that came closest simply used that model twice in the same equation. One for the cup and one for the air.

coder68yesterday at 10:17 PM

It does? There is a fast drop followed by a long decay, exponential in fact. The cooling rate is proportional to the temperature difference, so the drop is sharpest at the very beginning when the object is hottest.

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bryan0yesterday at 10:24 PM

Are you sure? I believe Newtown's law of cooling says the temperature will drop sharply at the beginning:

dT/dt = -k(T_0 - T_room)

so T(t) = T_room + (T_0 - T_room) exp(-kt)

exp(-x) has a fast drop off then levels off.

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lacunaryyesterday at 11:15 PM

probably dominated by the cup as the ambient temperature initially and then as air/the counter top as the ambient temperature on the longer time scale, once the cup and the liquid near equilibrium