if by Poiseuille’s Law, the greater the radius/diameter of a tube the faster the flow, why does water flow faster out of a hose when you put your thumb over the nozzle?

Question

if by Poiseuille’s Law, the greater the radius/diameter of a tube the faster the flow, why does water flow faster out of a hose when you put your thumb over the nozzle?

In: 7

Answer 1

To add on to everyone else’s answers, a good way to visualize the difference is to fill buckets. Fill one with your thumb covering the tip of the hose, and fill one uncovered, and time both. This will show you the difference between velocity and volumetric flow rate.