Uploaded on 2019-05-06 by Lance Villaruel

THIS IMAGE IS FROM THE INTERNET The image chosen is of Trafalgar square in central London. The water in the fountain pool can be considered as a stock and in the water coming out of the fountain itself is a flow. The stock effective remains the same while the water from the fountain flows. But to do so there must also be an equal outflow via drainage. One very cold days when the the fountain pool freezes rate of change of the flow and the stock of water changes drastically to the point of stagnation. Let people in the pool on hot days and increasing the flow for hygiene might be an improvement The number of people in the square at any time also varies as people walk in an out. But those who spend some time such as an hour more, could be considered as a flow and is significant with respect to the capacity of Tranfalgar square. On new years eve the amount of people entering can exceed those leaving causing a safety hazard. Diverting the flow of people to other attractions to improve safety might help.