Problema Solution
Hot custard in heated at a temperature of 194°F. It is then allowed to cool in the refrigerator at a temperature of 41°F. The custard cools to 140°F in 20 minutes. What will be the temperature of the custard after 80 minutes?
Answer provided by our tutors
We need to calculate a constant 'k' for cooling, so we use the following equation to solve for 'k' after the custard has cooled from 194F to 140F in 20 minutes (expressing 20 minutes as hours, 20/60):
140=41+(194-41)e^(k(20/60))
k=-1.30595
So knowing the cooling constant we can solve for the temperature after 80 minutes:
t=41+(194-41)e^(-1.30595)
t=82.45
So the custard would have cooled to approximately 82F after 80 minutes.