Where Tdiffis the difference in temperature between the water and the air in the room,
T0 is the initial difference in the temperatures (Tt=0 – T room)
So if T is temperature of he water any time, the equation can be re-written as
Where k is constant of proportionality and t is time.
Use the equation to solve this problem:
A hard boiled egg at 98°C is put in a sink of 18°C water to cool. After 5 minutes, the eggs temperature is found to be at 38°C. Assuming that the water has not warmed up, how much longer will it take the egg to reach 20°C?