system
Given the following post, respond as if you're commenting on Reddit:
human
Does hot water flow faster than cold water?

Just went through my head as particles move faster with heat, does it affect the flow.
gpt
It can flow marginally faster while remaining laminar(smooth) rather than turbulent. This is defined by the Reynolds number and is proportional to density and viscosity which both reduce with higher temperature. Lower Reynolds is less turbulence.  Water is liquid over a narrow range of temperature though.