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A smaller inflow can still increase a stock

A stock is an amount stored; a flow is a rate entering or leaving it. A reservoir grows when inflow exceeds outflow. If outflow stays unchanged, reducing inflow slows that growth but does not necessarily reverse it. This distinction also helps interpret accumulated pollutants or stored materials. State the period and units so that a stored amount is not confused with an annual rate.

Practice

With outflow unchanged, a pollutant enters a reservoir more slowly than before but still faster than it leaves. What happens to the stored amount?