Thermodynamics are hard?

Question

The burner on an electric stove has a power output of 2kW. A 660 g stainless steel tea kettle is filled with 20 degree C water and placed on the already hot burner. If it takes 2.60 min for the water to reach a boil, what volume of water, in cm^3, was in the kettle? Stainless steel is mostly iron, so you can assume its specific heat is that of iron.

Answer 1

Assuming no losses (if you belive in Santa...but we have no chice)
Pin= 2E3W
T1=20+ K(0C)
T2= 100 + K(0C)
T2-T1= 80 K

t=2.60 x 60=156 s

Q=Pin t= 2E3 x156=
Q=(m1Cp(H2O) + m2Cp(Fe))(T2-T1)

Q=Pt=2,000 x 156=3.12 E+5 J

m1= [Q/(T2-T1) - m2Cp(Fe)]/(Cp(H2O) where
Cp(Fe)= 450 J/kg K
Cp(H2O)= 4.181 E+3 J/kg K

m1= [3.12 E+5/(80) - 0.6 x 450 ]/ 4.181 E+3
m1=0.87 kg