# If I lift a submerged hose over 35 feet above the water's surface, what's in the top foot?

I've been arguing with a friend about the whole "perfect vacuum" concept. He and I agree that the most powerful vacuum pump in the world couldn't pump water more than ~34 feet above the surface of a regular elevation lake. I changed the problem slightly, and I'm not sure what would happen.

1. Submerge a hose such that it was completely filled with water
2. Cap off the top end
3. Start pulling it out of the water by a crane
4. Make sure the bottom end stays submerged

If you pulled the hose 40 feet out of the water, what would be in the top 6 feet of the hose? A "perfect vacuum"? Gaseous water? Liquid water?

-
The theoretical pumping limit for a suction pump is approximately thirty-four feet at sea level, and less at higher altitudes (about 1 foot less per 1000 feet). That is the limit regardless of the motor size connected to the pump because suction is limited to one atmosphere of negative pressure. Over 34 feet you would be pulling a perfect vacuum. Reference: windsun.com/Solar_Water_Pumps/pumpinfo1.htm – Argus Jun 9 '12 at 4:38