Question

When we throw water on floor first it starts flowing but after sometimes it stops . why?

Answer 1

When a fluid flows there is friction resisting the motion. Water with a much lower viscosity will travel much faster down a smooth surface and the frictional force between the water and the surface is much smaller.However if water flows across a rough surface it will travel down more slowly than on the smooth surface. Because the surface is rougher,the friction force is stronger and the velocity is slower.Due to this friction force at a rough surface flow of water stops and there is no velocity or movement at the surface.