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Can we float an ocean liner in bucket full of water spread to a large area?
Depends on how big the bucket is?
I suppose in theory, if you have a 'bucket' shaped exactly like the hull of the ship with just a tiny additional tolerance, the ship could technically 'float' in just the amount of water required to fill the gap.
A vessel floats once it has displaced a mass of water (from the volume it is floating in) equal to its own 'displacement', hence the term.
rcgldr has correctly debunked your idea, which is one that would have little or no displacement of water and absolutely would not work. You clear understand the displacement (your second sentence) so I'm puzzled why you would offer your first sentence.
Now I put the boat in the bucket, 10,000,000 pounds of water is displaced and flows out over the edge leaving a 10,000,000 pound boat floating in 1 pound of water.
both rcgldr and cmb are saying the same thing and both are right.
Suppose I have a boat with a hemispherical hull that displaces 10,000,000 pounds of water. I have a hemispherical bucket that containt 10,000,001 pounds of water. The radius of the bucket is very slightly larger then the radius of the hull. Now I put the boat in the bucket, 10,000,000 pounds of water is displaced and flows out over the edge leaving a 10,000,000 pound boat floating in 1 pound of water.
You sure about that? If the water flowed over the edge of the bucket then the ship is no longer displacing anything...
Nope. I don't believe it. They are NOT the same. If your bucket RETAINS the water that is displaced then the ship will float. If the water flows over the side and is gone, there's nothing left holding up the boat.
Nope, I'm still not buying it. It just not going to work the way you say it will. It is NOT displacing any water unless that water is still around to push on the bottom of the boat.
The water is all around - in the form of a thin film. What is important is that water exerts pressure on the hull - and it exerts pressure everywhere on the hull surface, just like it would in the case of the boat in the ocean. Yes, in theory it is possible to float an air carrier in a gallon of water.
The water is all around - in the form of a thin film. What is important is that water exerts pressure on the hull - and it exerts pressure everywhere on the hull surface, just like it would in the case of the boat in the ocean. Yes, in theory it is possible to float an air carrier in a gallon of water.
The water is all around - in the form of a thin film. What is important is that water exerts pressure on the hull - and it exerts pressure everywhere on the hull surface, just like it would in the case of the boat in the ocean. Yes, in theory it is possible to float an air carrier in a gallon of water.
Hm ... I just can't see it at all. What is supporting the boat? There certainly is not enough pressure from a gallon of water to support it, so why does it not just move down to the bottom of the container (and thus not be floating)?
I'm an engineer, not a theorist and I say it won't work.![]()
The reason that it was floating to begin with is because that water was applying pressure to the boat, equal to the boats weight.In your scenario you have no source of pressure. (Other than the contrived compressed state of the water).
Pressure depends on height of the water (column) not the volume of water.
I meant force.
force = pressure * area
Since neither pressure nor the area change, why should the force change?
It is not uncommon these days, with space being at a premium and particularly miltary vessels coming in all shapes and sizes, for a wet dock to be pretty much as I described it - more boat than water!
For sure, there may well be less water in the wet dock than there is displacement of the vessel. This is known.
Sorry - yet another occasion to put your 'intuition' aside and trust what the physics says.
Borek, you have a magical barrier that contains the water in its thin film, or else what stops the water from shooting out of this bucket under immense pressure?
You are almost right - you just forgot we don't care about the bucket, we care about water. Yes, if the bucket is not strong enough, it will break. But the hull doesn't touch the bucket, so the ship floats in the water.
I never once suggested that the bucket wasn't strong enough. I suggested that you cannot compress the water to create the buoyant force required for floatation.
If you were to put a "cap" on the bucket so the water is contained within the bucket, then it would be the cap that is applying the retarding force, not the water. And that doesn't meet any definition of floatation.
Do you need a cap, when the ship floats in a lake?
Build a second hull around the floating ship, at small distance (no contact). Still floating?
Fix the second hull to the ground and pump out the rest of the lake. Still floating?
Do you need a cap, when the ship floats in a lake?
Build a second hull around the floating ship, at small distance (no contact). Still floating?
Fix the second hull to the ground and pump out the rest of the lake. Still floating?
no it is not still floating.
At which point does it stop floating? When you build the second hull or when you remove the water outside the second hull?
I meant force. Show me where your force comes from. Explain how a thin film of water (uncompressed) exerts 10 000 000 lbs worth of force in any scenario.
Do you agree amount of water in the third one can be just a bucket?
Let's say the second hull is build from the bottom of the lake, piece by piece.It stops floating when you build the second hull. The second hull will still float, but there will be contact between the second hull and the ship.