The Coffee Cooling Paradox · AI Generator #GEN-38DB969B
Physics · thermodynamics
Problem
A barista notices something strange while serving coffee in two identical ceramic mugs. She pours 200mL of coffee at 85°C into the first mug and lets it cool in the 20°C room for exactly 3minutes, after which its temperature is 75°C. For the second mug, she pours the same amount of coffee at the same initial temperature, but immediately adds 50mL of milk at 5°C, then lets this mixture cool for the same 3minutes. Assume that cooling follows Newton's law of cooling, milk and coffee have the same specific heat capacity and density, and mixing is instantaneous with no heat loss during mixing. What is the final temperature of the coffee-milk mixture?