Question

why density does not affect fluid friction??

Answer 1

Dear Student
Your statement is not entirely true. Density of a fluid doesn't effect the friction directly. Its the change in viscosity that affects the friction. A liquids viscosity is measured by its resistance to flow. Density is the amount of mass occupying a space. Observe oil and water.The two properties aren't related. Both are constant physical properties of a substance at a specific temperature. If you heat a viscous product like oil, it will expand, decreasing density, and thin out, decreasing viscosity. However, the changes are a result of the temperature change, not of a relationship between viscosity and density.