At a fabrication plant, a hot metal forging has a mass of 66.8 kg and a specific heat capacity of 437 J/(kg C°). To harden it, the forging is quenched by immersion in 785 kg of oil that has a temperature of 25.0 °C and a specific heat capacity of 2770 J/(kg C°). The final temperature of the oil and forging at thermal equilibrium is 61.7 °C. Assuming that heat flows only between the forging and the oil, determine the initial temperature in degrees Celsius of the forging.

Answer 1

At final thermal equilibrium, the heat gained by the oil equals the heat lost by the metal. Write that as an equation and solve for the initial temperature of the metal, To.
(To - 61.7)*66.8*437 = (61.7-25)*785*2770