how siphoning works, considering the issues of pressure and speed.?

Question

My science question for the day..any body kind enough to elaborate for me? Thanks a lotsa..

Answer 1

To start a siphon off, a 'suction' has to be applied to the delivery end.
This end is then quickly transferred into a much lower placed receiver...holding a thumb over the outlet will keep the system liquid full while placing it at the lower level.
As the transfer starts, the velocity of the liquid leaving the open end will cause a lower pressure than atmospheric, just like the original 'suction' did at the start..
The atmosphere acting on the liquid area of the supply vessel is a much greater force than that of the much smaller area at the bottom of the delivery end. This difference in forces, as long as the supply end of the tube remains submerged and the delivery end does not become submerged and remains well below the level of liquid in the upper vessel, maximum transfer rate will continue.
Allowing the level in the receiver to rise and cover the outlet of the pipe, the higher it gets, the lower the 'force' difference will be and the transfer will slow down..

Answer 2

Concerning issues of pressure and speed, the velocity of the liquid will increase the lower the exit point is from the entrance point. The wider your hose is will then tell you how much fluid/time comes out. In short, have the container you're siphoning into be as low as possible and use the widest hose you can find for quick siphoning.

Answer 3

Not sure, but this sure has me thinking about buying a locking gas cap.