Answer:
An ice cube melting
Explanation:
Ice needs to be maintained at a temperature below the freezing point of water to remain solid. On hot summer days, most people take ice from their freezer to cool off their drinks. While doing this, they (may or may not) witness the first and second laws of thermodynamics. (EX) someone might put an ice cube into a glass of something warm and then walk away without drinking it. Within an hour or two the ice has melted but the temperature of the drink has cooled. This is because the total amount of heat in the system has remained the same, but has just gravitated towards equilibrium, where both the former ice cube (now water) and the drink are the same temperature. This is, of course, not a completely closed system. The drink will eventually become warm again, because of the natural heat that is transferred glass and its contents.
