Problem from Nagle & Saff
Two friends sit down to talk and enjoy a cup of coffee. When the coffee is served, the impatient friend imme-diate adds a teaspoon of cream to his coffee. The relaxed friend waits �ve minutes before adding a teaspooon of cream (which has been kept at a constant temperature). The two now begin to drink their coffee. Who has the hotter coffee? Assume that the cream is cooler than the air and use Newton�s Law of Cooling.