A blacksmith drops a 0.7 kg horseshoe at 1200 °C into 0.5 L of water at 30 °C, leading to a discussion on how much water boils off. The key equations involve heat transfer, where the heat lost by the horseshoe equals the heat gained by the water and the heat required to convert water to steam. The process first heats the water to 100 °C before any boiling occurs, and the final equilibrium temperature is determined by the heat exchange. Calculations reveal that approximately 0.0922 kg of water boils off, demonstrating the conservation of energy principle in thermal systems. This scenario illustrates the complexities of heat transfer and phase changes in thermodynamics.