2 ms·
https://physics.stackexchange.com/questions/5265/cooling-a-cup-of-coffee-with-help-of-a-spoon/5510#5510 https://physics.stackexchange.com/questions/5265/cooling
by sp332 4y ago
https://physics.stackexchange.com/questions/5265/cooling-a-cup-of-coffee-with-help-of-a-spoon/5510#5510 https://physics.stackexchange.com/questions/5265/cooling-a-c...
To counteract a 2-centigrade-degree drop per minute, you'd only need 35W to keep 250ml at a constant 85C. (Or 65C if that's where you start it.)
- tinix 4y agoso you could insulate the coffee so it doesn't drop in temperature, induction heating a vacuum flask maybe?
- MayeulC 4y agoI bet adding a lid substantially decreases the power requirements. Nit: please use Celsius (and "°C" if you can)
- sp332 4y agoI prefer centigrade over Celsius because it's not named after a person. Also I wanted to be clear that it's a two degree drop, not 2°C.
- eru 4y agoIf you want to be funky with your units, I suggest measuring 'coldness' instead of temperature and expressing it in bit per joule (or more conveniently Gibibyte per nanojoule). See https://en.wikipedia.org/wiki/Thermodynamic_beta https://en.wikipedia.org/wiki/Thermodynamic_beta > Though completely equivalent in conceptual content to temperature, β is generally considered a more fundamental quantity than temperature owing to the phenomenon of negative temperature, in which β is continuous as it crosses zero whereas T has a singularity.[6] > In addition, β has the advantage of being easier to understand causally: If a small amount of heat is added to a system, β is the increase in entropy divided by the increase in heat. Temperature is difficult to interpret in the same sense, as it is not possible to "Add entropy" to a system except indirectly, by modifying other quantities such as temperature, volume, or number of particles.