Sir Isaac Newton investigated the cooling process of water temperature and showed that the temperature change is exponential in time and can be predicted by

Tdiff=T0e

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

T-T room=(Tt=0-Troom)e

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?

Tdiff=T0e

^{-kt}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

T-T room=(Tt=0-Troom)e

^{-kt}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?

PLEASE HELP ME :D