When I receive a cup of coffee, and I'm not yet ready to drink it, will it lose less heat if I immediately add the milk, rather than wait to add the milk just before I drink it?
(Bonus points for estimate of difference based on 5 minute wait!)
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1More on coffee & milk. More on tea & milk. – Qmechanic Jun 08 '15 at 20:23
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1Newton's law of cooling http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/diffeqs/cool.html – Jun 08 '15 at 20:59
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3possible duplicate of Does tea stay hotter with the milk in it? – ProfRob Jun 08 '15 at 21:30
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Yes! You have to think about the amount of energy that is hold in the coffee. The amount is (almost) exactly the same the moment before you add the milk than just in the moment after adding it. So if you consider the energy of a cup at room temperature as zero energy, the amount of energy stays the same as the milk adds no energy. But(!) the temperature difference to room temperature lowers when adding the milk! And what is closer to room temperature will slower lose its energy to the surroundings. The key of this really lies in the difference of the temperature. If the difference is high u will fast be loosing a lot of energy, if its not the energy stays longer in the coffee. (Energy is just proportinal to Temperature)
Per @AcidJazz above: Newton's law of cooling: ugrad.math.ubc.ca/coursedoc/math100/notes/diffeqs/cool.html
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