Short Hose and Long Hose

Let's take a look!

Watch the video on YouTube.

What kind of experiment is this?

Experimental procedure and explanation:

• We drain water from a tank using the siphon principle and study how the flow speed varies with the length of the hose.
• When a short hose (1-m long) is used, the water flows smoothly.
• When a long hose (9-m long) is used, the flow speed reduces.
• When a fluid (liquid or gas) flows through a tube, viscous friction acts between the inner wall of the tube and the fluid; this friction is due to the viscosity of the fluid. The friction causes resistance to the fluid flow. The resultant loss of fluid energy is called pipe friction loss.  
• For hoses having the same diameters and same flow rates, pipe friction is proportional to the tube length. Therefore, in this experiment, the resistance of the long hose is large and the flow speed is reduced. 
• When a fluid flows through a tube, excessive length is not favorable due to the larger energy loss.

[Keywords]	Pipe friction loss
[Related items]	Large Diameter Hose and Small Diameter Hose
[Reference]	“The Wonders of Flow,” Japan Society of Mechanical Engineering, Kodansha Blue Backs pp. 182–185. “Illustrated Fluid Dynamics Trivia,” by Ryozo Ishiwata, Natsume Publishing, pp. 180–181.