Final answer:
To cool a drink, adding ice cubes is the most effective method. Ice absorbs heat when melting, keeping the drink at a consistent, cool temperature due to thermal equilibrium. This takes advantage of the endothermic properties of the phase change from solid to liquid.
Step-by-step explanation:
To cool down a drink on a hot day, you can add ice cubes to the beverage. This is effective because the ice requires heat to melt, thus absorbing energy from the drink and lowering its temperature. The process where ice maintains the drink at 0°C in a hot environment until it fully melts is due to the thermal equilibrium between the ice and the liquid water.
In other words, incorporating ice into a drink leverages the endothermic process of melting to remove heat from the drink, maintaining it at a constant, cool temperature. This same principle is utilized in devices such as a "swamp cooler," where evaporation provides cooling. Adding ice not only provides immediate cooling, but also keeps drinks at a consistent, chilled temperature over a longer period, which is highly desirable on a hot day.