# Flow through pipe while being lifted from water [closed]

The setting is as follows. A hollow pipe (flooded) with radius R-pipe is being lifted from below the water surface (totally submerged) to above the water surface with a speed of v1. The pipe is closed at the top and the bottom. The crane that is lifting the pipe does not want to lift the water that is inside the pipe as well. What size holes (how many) do you have to drill at the top of the pipe and the bottom of the pipe so natural flow through the pipe occurs (if this even does occur)?

Also, when the pipe is being lifted from the water (so while a part is still in the water) you don't want the water level in the pipe to be higher than the level of the water surface (you don't want to lift the extra kilo's). I thought this was the case:

But I think there is something wrong. So how big should the hole at the top and bottom be related to the lift speed and the height between the two holes so water flows through the pipe? Does water even flow through when the holes are in the side of the pipe?

## closed as off-topic by sammy gerbil, Jon Custer, Kyle Kanos, Asher, Rory AlsopNov 25 '17 at 20:47

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better" – sammy gerbil, Jon Custer, Kyle Kanos, Asher, Rory Alsop
If this question can be reworded to fit the rules in the help center, please edit the question.

• -1. Not clear what you are asking. What does "so natural flow through the pipe occurs" mean? Natural flow occurs when the pipe has no top or bottom at all, and does not restrict the free movement of water. Any top or bottom will affect natural flow to some extent. – sammy gerbil Nov 23 '17 at 12:49
• @sammygerbil: I disagree somewhat. It could have been formulated better but it's quite clear what the question means. – Gert Nov 23 '17 at 13:08