Using Newton's Law of Cooling, the given are:
Temperature of the first bath (Ta1): 25C
a(final temperature)= 50C, b (initial temperature)=100C
x-y is the difference in time. In the first bath, 150s
dT/dt=-k(T-Ta)
![\int\limits^a_ b{(dT/(T-Ta1))} \, dt = \int\limits^x_y{-k} \, dt](https://tex.z-dn.net/?f=%5Cint%5Climits%5Ea_%20b%7B%28dT%2F%28T-Ta1%29%29%7D%20%5C%2C%20dt%20%3D%20%5Cint%5Climits%5Ex_y%7B-k%7D%20%5C%2C%20dt)
ln (T-25) [from a=100 to b=50]= -k*150
ln ((50-25)/(100-25))= -k*150
Solving for k=7.324081X10^-3
For the second bath: find Ta2 with dt=120s
dT/dt=-(7.324081x10^-3)*(T-Ta2)
![\int\limits^a_ b{(dT/(T-Ta2))} \, dt = \int\limits^x_y{-7.324081x10^-3} \, dt](https://tex.z-dn.net/?f=%5Cint%5Climits%5Ea_%20b%7B%28dT%2F%28T-Ta2%29%29%7D%20%5C%2C%20dt%20%3D%20%5Cint%5Climits%5Ex_y%7B-7.324081x10%5E-3%7D%20%5C%2C%20dt)
ln (T-Ta2) [from a=100 to b=50]= -(7.324081x10^-3)*120
ln ((50-Ta2)/(100-Ta2))= -(<span>7.324081x10^-3)</span>*120
Solving for Ta (second bath temperature)=
14.49 degrees Celsius