Less 1 inch below water = 179 inches above water.
Area of 4 inch I.D.: pi × (4÷2)^2 = 12.56637 sq.in.
Water volume: 12.56637 × 179 = 2249.38 cu.in. water.
Water volume: 2249.38 ÷ (12^3) = 1.301725 cu.ft. water.
Weight of water: 1.301725 × 62.3 = 81.0975 lbs.
Then also add the weight of the pipe itself, maybe 5 pounds, for a total weight of 86 pounds.
To raise the water filled pipe to this height you need to apply a lifting force, which starts at near zero lbs when the pipe is fully under water and progresses to 86 pounds as the pipe reaches full extension up out of the water.
Now insert a hollow tube, say 3 inch diameter by 14 feet.
It will displace about 43 pounds of water. So you need to push the hollow tube downward with a force that starts at zero pounds and progresses up to about 43 pounds.
Now when you release the hollow tube, it floats up into the pipe and displaces water, which gravity will cause to flow down out of the pipe, thus wasting potential energy.
But now your pipe with its floating hollow tube no longer weighs 86 pounds.
The suspended pipe with the hollow tube inside weighs about: 86 - 43 = 43 lbs.Jon H. wrote:Now how much does the suspended tube above the water weigh? The same as if it were completely filled with water.
Which depends upon the actual size and weight of the float inside the pipe.
There is no way to harness perpetual energy from water and floats. People have been trying for hundreds of years. If there were a method, then it would have been discovered by now. The primary reason goes back to gravity being conservative. It takes the same energy to lift water as the water gives back when it falls. Water inside tubes, etc. just makes the mechanism harder to understand.