I've made an experiment to verify Newtn's law of cooling, but while doing the analysis, my results don't fit accurately with the data collected (303 data using a sensor). According with my initial conditions such as $T_R=21.8°C$ (room temperature) and $T_o=80°C$ (initial temperature) I should obtain something like:


Instead, I obtain the following:


So, I was wondering if something's missing or maybe Newton's law is not enough to describe the cooling of an object.

  • 1
    $\begingroup$ Have you read the first paragraph of the Wikpedia article on Newton's Law of Cooling? It gives at least two examples of likely sources of error. $\endgroup$
    – The Photon
    Sep 20, 2020 at 3:06
  • $\begingroup$ Don't you mean 58.2? So you don't match the initial temperature? I hope you plotted (T-21.8) vs t on a semi-log plot and fit a straight line. Is that what you did? $\endgroup$ Sep 20, 2020 at 3:14
  • $\begingroup$ @ChetMiller yeap, that's what I did and indeed I don't match the initial temperature. $\endgroup$
    – Syn1110
    Sep 20, 2020 at 4:25

1 Answer 1


There are two heat transfer resistances involved here: the heat transfer resistance outside, from the surrounding fluid to the surface, and the heat transfer resistance inside the object, from the surface to the internal region. Newton's law assumes that the overall resistance is dominated by the outside resistance (which is typically nearly constant). However, the inside resistance varies from a low value to a higher asymptotic value over time, and, if this resistance is significant, it results in a higher overall resistance that varies with time.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.