Answer:
49.12 °C
Explanation:
[tex]m_{g}[/tex] = mass of gold sheet = 12 g
[tex]c_{g}[/tex] = specific heat of gold = 0.129 J/g°C
[tex]T_{gi}[/tex] = initial temperature of gold sheet = 15 °C
[tex]m_{i}[/tex] = mass of iron sheet = 20 g
[tex]c_{i}[/tex] = specific heat of iron = 0.449 J/g°C
[tex]T_{ii}[/tex] = initial temperature of iron sheet = 55 °C
[tex]T_{f}[/tex] = Final equilibrium temperature
Using conservation of heat
[tex]m_{g} c_{g} (T_{f} - T_{gi}) = m_{i} c_{i} (T_{ii} - T_{f} ) \\(12)(0.129)(T_{f} - 15) = (20)(0.449)(55 - T_{f})\\(1.548) (T_{f} - 15) = (8.98) (55 - T_{f})\\T_{f} = 49.12 C[/tex]