Answer:
110.03 °F is the temp of the cake after 35 minutes.
Explanation:
Newtons Law of Cooing is given by:
[tex]T=C+(T_o-C)e^{-kt}[/tex]
t = Time it taken by an object to cool from the temp [tex]T_o[/tex] to the temp T
C = temperature of the surrounding
k = Constant that is associated with the cooling object
We will first calculate the value of k.
[tex]T_o=207^oF,T=138^oF,C=69^oF,t=20 min[/tex]
Substituting the values in a given formula:
[tex]138^oF=69^oF+(207^oF-69^oF).e^{-k20 min}[/tex]
[tex]k=0.03465 min^{-1}[/tex]
The temperature of the cake after 35 min:
[tex]T_o=207^oF,T=?,C=69^oF,t=35 min,k=0.03465 min^{-1}[/tex]
[tex]T=69^oF+(207^oF-69^oF).e^{-(0.03465 min^{-1})35 min}[/tex]
T = 110.03 °F
110.03 °F is the temp of the cake after 35 minutes.