Question

At a fabrication plant, a hot metal forging has a mass of 78.5 kg and a specific heat capacity of 426 J/(kg C°). To harden it, the forging is quenched by immersion in 788 kg of oil that has a temperature of 30.3 °C and a specific heat capacity of 2770 J/(kg C°). The final temperature of the oil and forging at thermal equilibrium is 55.4 °C. Assuming that heat flows only between the forging and the oil, determine the initial temperature in degrees Celsius of the forging.