A Camper Is About to Drink His Morning Coffee

A camper is about to drink his morning coffee. He pours 400 grams of coffee, initially at 75.0°C into a 250-g aluminum cup, initially at 16.0°C. What is the equilibrium temperature of the coffee-cup system, assuming no heat is lost to the surroundings? The specific heat of aluminum is 900 J/(kg·K) . Assume that the specific heat of coffee is the same as the specific heat of water.

A) 45.5°C
B) 62.0°C
C) 65.0°C
D) 68.0°C
E) 71.0°C