What is the formula for calculating the temperature change of a liquid as a function of the liquid's temperature, the external temperature, and time? askscience

An example:

If I have a cup of water at 75 degrees farenheit and I put it in the refrigerator which is at 40 degrees farenheit, how long will it take for the water to reach 50 degrees farenheit?

And I imagine you could move the same formula around to phrase the question as "if I leave a cup of room temperature water in the 'fridge (40 degrees) for 30 minutes, what will its temperature be?"

Submitted April 18, 2015 at 06:35AM by hallflukai http://ift.tt/1DuFZVH askscience