Final answer:
Internal friction (viscosity) reduces fluid flow rate by increasing resistance. Greater pressure difference drives higher flow rates, as indicated by the equation Q = Av. High internal friction can significantly impact velocity and flow rate for incompressible fluids.
Step-by-step explanation:
The relationship between internal friction and fluid flow rate is quite significant in understanding fluid dynamics. Internal friction, often represented by viscosity, is a measure of a fluid's resistance to flow. When a fluid flows through a pipe or any other conduit, it experiences friction along the walls and within the fluid layers that can reduce the flow rate.
Considering the relationship between pressure difference and flow rate, it is evident that flow is driven from a region of high pressure to a region of low pressure. Hence, the larger the pressure differential, the higher the velocity and consequently the greater the flow rate. This is represented by the equation Q = Av, where 'Q' is the volume flow rate, 'A' is the cross-sectional area, and 'v' is the average velocity.
However, as internal friction or viscosity increases, it hinders the movement of fluid particles, which in turn can reduce the flow rate for a given pressure difference. For incompressible fluids, the concept becomes even more critical as the equation of continuity, ensuring conservation of mass, dictates that the product of cross-sectional area and velocity (A*v) must be constant along any point in a streamline, so any increase in internal friction would directly result in a change in velocity and hence flow rate.