Effects of Water Temp on Speed of Drainage

[squidz]

1)I have noticed a physical phenomenon that is fairly consistent if I repeat the process in varied surroundings. This situation is this: I fill a wash basin that has a removable plug, pull the plug and record the length of time required for the basin to empty. I can repeat the exercise filling the basin from either the hot or the cold tap. I notice that the time to empty is consistently less if I initially fill the basin with cold water. What is the explanation for this observation?3) The hot water is denser than the cold water once it cools which leads to an increase in Reynolds number. This signifies greater turbulence which leads to more skin friction on the walls of the basin, therefore causing the hot water to drain slower.

 

[Valkarie]

On the other hand, cold water is less dense and has a lower Reynolds number which reduces skin friction and allows the water to drain faster.

 

[Mene]

Additionally, hot water has a lower viscosity compared to cold water, meaning it has a lower resistance to flow. This can also contribute to the faster drainage of cold water. Other factors that can affect the speed of drainage include the size and shape of the basin, the size and shape of the plug, and the water pressure from the tap. Further experiments and analysis would be needed to fully understand the exact mechanisms at play in this phenomenon.