If [color=#c51414]WATER[/color] / [color=#0a971e]MONEY[/color] comes into a [color=#c51414]BATHTUB[/color] / [color=#0a971e]BANK[/color] at a constant rate[br]and leaks out a rate proportional to the [color=#c51414]HEIGHT[/color] / [color=#0a971e]AMOUNT[/color] of the[br][color=#c51414]WATER[/color] / [color=#0a971e]MONEY[/color] in the [color=#c51414]BATHTUB[/color] / [color=#0a971e]BANK[/color], then an equilibrium [color=#c51414]HEIGHT[/color] / [color=#0a971e]AMOUNT[/color] [br]of [color=#c51414]WATER[/color] / [color=#0a971e]MONEY[/color] in the [color=#c51414]BATHTUB[/color] / [color=#0a971e]BANK [/color]can be reached.[br][br]You can use this applet to explore how the equilibrium depends[br]on the rate of flow into and the rate of flow out of the [color=#c51414]BATHTUB[/color] / [color=#0a971e]BANK[/color].[br][br]Clearly, the [color=#c51414]BATHTUB[/color] / [color=#0a971e]BANK[/color] is a metaphor for many equilibrium situations[br]that arise because of competing rates. Can you think of others?[br][br]You can watch an animation by clicking on the "play" icon in the lower[br]left hand corner of either window.