A 29 g aluminum spoon (specific heat 0.904 J/g•°C) at 24°C is placed in 184 mL (183 g) of coffee at 82°C and the temperature of the two become equal.
(a) What is the final temperature (in °C) when the two become equal? (Assume that coffee has the same specific heat as water, 4.1801 J/g•°C.)
(b) The first time a student solved this problem she got an answer of 86°C. Explain why this is clearly an incorrect answer.
Coffee is always lukewarm by the time you get around to drink it, and so is the spoon.
The temperature of the coffee cannot increase when a colder spoon is placed in it.
The student forgot to convert the temperature to kelvins when working this problem.
The temperature of the spoon should decrease when it is exposed to the coffee.