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### Does water have a minimal thickness because of van der waals force?

I have read this question: The thickness of a puddled sheet of water https://en.wikipedia.org/wiki/Surface_tension#Puddles_on_a_surface The liquid mass flattens out because that brings as ...
30 views

### Will we be able to experience huge waves one after the other if we were near a strong gravitational field?

I was wondering if we will have huge waves due to the presence of a strong gravitational field nearby earth? If our planet is rotating around the gravitational field, is there a possibility for ...
77 views

### What would happen to the water bodies if gravity ceased to exist on Earth?

If water stopped flowing (it would stop flowing downwards from mountains and all) then, would it start rising upwards? If it floats on the space ( I say space because there'd not be any atmosphere) ...
38 views

### Water climbing up sandpile against gravity?

I have seen a bucket full of water, and sand in it so that the sand just creates a pile just above the water level, and the sand that is above the water level is first dry. As time passes, the water ...
138 views

### Force of Body Impact Upon Water

So in 2014 I fell from 70 feet and landed flat on my back on slowly moving water (.5ft/sec) on the Willamette River. I weighed aproximately 190 pounds at the time. I was curious if someone would help ...
200 views

### Buoyancy and non-horizontal water

With horizontal water and downwards gravity, buoyancy pushes upwards. However, in which direction is it pushing (say a boat) when the gravity is downwards but the boat is on a non-horizontal ground ...
47 views

### Energy Creation Using Water, Generators, and a Pump

So a friend and I are arguing over an infinite energy idea that he had about using gravity, that is an almost infinite source of energy. Water to use to push a generator by dropping and hitting the ...
81 views

### If falling from height into water, at what height would a buoyancy aid be more likely to cause injury?

There are strict requirements for lifejacket / buoyancy aids in the offshore oil & gas industry, requiring them to be worn when working above the water. Some places have been noted to be using a ...
494 views

### How to start a siphon with a tube filled with liquid?

If I have a tube filled with water, whose one end I dip into a container filled with water. If I release the other end will it start a siphon ?
137 views

### How wide is one's pee stream on the Moon? [closed]

This morning it occurred to me that on the Moon, with one-sixth of Earth's gravity, your pee stream should be wider, because you're peeing at the same rate, but there is weaker gravity to stretch it ...
87 views

### Why water clouds don't fall when there is strong wind and no updraft?

I see clouds traveling at speed where is no updraft, keeping the same altitude, in windy conditions...why they don't fall? Also I experienced clouds hovering in valleys and stationary clouds above ...
1k views

### Does the flow of water increase if it has to flow over a height and then to a depth which is more than its height?

Please suggest a formula also to calculate the same, if the measurements of pipe and tank are known
2k views

### Bottle with water and air, all in a vacuum: what happens?

You have a bottle half with water and half with air. The environment is a vacuum that the bottle is in. The environment does have gravity. So if we flipped the bottle so that the bottom of the bottle ...
6k views

### Does an object float more or less with more or less gravity?

This might be a stupid question, but I'm a newbie to physics. An object less dense than water (or any other fluid, but I'm going to use water for this example) floats normally on Earth when placed in ...
114 views

### Would a world filled with water collapse?

I don't know if this is considered off-topic but, If you took a planet (assumed solid) and filled it with water continuously/non-stop what would eventually happen to the water? Would gravity at some ...
55 views

### Why do water droplets not form on large openings such as pipes?

When you have an object with a small opening, such as a pipette, water droplets form and hang easily. However, when you have a larger opening such as a pipe, the same water droplets do not form. Is ...
3k views

### Better explanation of why an object floats: density? or buoyancy in equilibrium with object's weight?

Across StackExchange, you see two explanations for why an object floats: The buoyant force, equal to weight of displaced water, is in equilibrium with the object's weight. The density of the object ...
2k views

### Why do I sink then float in a swimming pool?

Was swimming this morning and observed something strange: if I stop treading water, hold my legs together, arms pressed against my sides, then I sink to about 3m below the surface, and then rise again ...
5k views

### A cup of water in ZERO gravity

What will happen if I try to pour a cup of water in zero gravity, into another empty cup? Will the water come out of the cup? The adhesive force between the water molecules and the interior of the cup ...
547 views

### What Is the Physics principle behind dropping a stone into a cup of water?

I have been doing an experiment about relationship between drop height of a stone and the loss of water in the cup it lands in. I found that after dropping the same stone into a cup with the same mass/...
3k views

### What is the effect of water 'climbing' over a cup via a wet string? [duplicate]

I have noticed (with tea bags, etc) that if you get the whole string wet, and you have one end inside the cup and the other end below the level of the liquid (outside), the water drains down the ...
674 views

### Calculating PSI generated by water entraining air as it flows down a pipe

This is the concept used in a trompe. Basically, the idea is that if we allow water to flow down a pipe and if that pipe has inclined air intake orifices near the top where the water enters, then the ...
752 views

### what is this force that is able to surpass an entire planet's force on it?

I have a wet teabag in an empty cup. If I will hold the teabag and touch the wall of cup with it, it will stick to the cup, like there would be glue or some magnetic field, but there's just water. So,...
120 views

### Could water physically makeup the core of a planet or otherwise large celestial mass?

Knowing very little about the nature of water, wondering how it might behave at the centre of a planet or centre of an another massive gravitational body. Could water take such pressures or might it ...
655 views

### Sandstone getting soaked with water [duplicate]

I have seen someone putting a sandstone in water. With only about 10% of the stone sitting in the water. One could see the stone getting soaked with water. So there must be a force, which lets the ...
3k views

### What is the largest sphere of liquid water that could exist in space held together under it's own gravity? [duplicate]

What is the largest theoretical sphere of liquid water that could exist in space held together under it's own gravity? I've always wondered if a planet the size of earth could exist as a single volume ...
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### How fast does water fall in the middle of a very very thick waterfall?

Let me create a very artificial experimental set up. Take a bathtub the size of Delaware and suspend it a mile above the ground. Fill it with water (though I'm not sure to what depth - and it might ...
3k views

### Why don't I feel pressure on my body when swimming under water?

If I put a couple of lead bricks on my foot, there would be a definite sensation of a heavy, perhaps even painful, force. Calculating the pressure for $20 kg$ of lead over a $100 cm^2$ area of my foot,...
652 views

### The physics behind The Great Flood [closed]

The book of Genesis floats (pardon the pun) some interesting numbers when discussing the Great Flood. For example, it rained for 40 days and 40 nights, and at the end of that time, the entire planet ...
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### Why does water flow out of an upside-down bottle? (Rayleigh Taylor Instability)

I am currently reading the excellent book An Indispensable Truth: How Fusion Power Can Save the Planet by Francis F. Chen and I came across this explanation. The Rayleigh–Taylor Instability ...