The hydrostatics tag does also apply to fluid-statics.

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6
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3answers
611 views

Why doesn't hydrostatic pressure glue objects to the seafloor?

Consider a cement block of the same density as sea-water resting on the (perfectly polished) seafloor. I also assume the side-faces of the cement block are highly polished, so that no vertical ...
1
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0answers
20 views

A block floating on water is pushed inside until it touches the bottom. Will the block come back? [duplicate]

A block floating on water contained in a vessel is pushed inside until it touches the bottom of the vessel and then released. Will the block come back? Bouyant force acts because the pressure on ...
2
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3answers
376 views

Question about buoyancy

I took an empty clear sphere with radius r, put some weight inside this sphere, and put in into the water. I calculate the buoyancy force as: Volume of the sphere = Volume of the water displaced ...
0
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2answers
145 views

Given a slanted pipe

Question: I have a pipeline that is tilted. I know the length of the pipeline, and the pressure (90psi) that is felt at the very bottom. I'm trying to find out how much liquid has leaked out if the ...
0
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0answers
9 views

Is there a relationship between maximum flow rate of a fluid through perforations in a cavity and the flow rate of the fluid in the cavity itself?

I have a scenario where water is flowing horizontally through a (rectangular) cavity. The underside of the cavity has a set of perforations that look something like: and I need to determine the ...
1
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2answers
840 views

Calculating pressure under water

Say I were calculating the pressure under 1 foot of water, in psi. I'm thinking the pressure is force per unit area, and should be equal to the force exerted by the column of water standing over ...
-1
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0answers
23 views

How do monitor arm mounts stay up? [closed]

What is the mechanism and also the name of the principle involved in engineering computer displays arm mounts? How does it allow up and down motion without the hinges just dropping the monitor (and ...
0
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0answers
49 views

Where is my helium gas balloons? [closed]

Forgive me if it is stupid question :-P. I bought some Helium gas balloons I leaved it to fly as we all do, then what happens to my balloon. How long it can survive without bursting in atmosphere? ...
0
votes
1answer
110 views

What is the physical fundamentals of Pascal's law

Pascal's law or the principle of transmission of fluid-pressure (also Pascal's Principle) is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible ...
0
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0answers
4 views

Siphon and a pressure gradient

It's claimed here that the pressure gradient is what sustains the flow in a siphon. But I'm not really accustomed to the term and don't see why it forms and why it sustains the flow. Can you please ...
1
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1answer
16 views

How do you compute pressure at a pipe inlet if the pipe is leaking between the inlet and the outlet/pressure measurement point [closed]

This is a real world problem: I have a vertical pipe (a well ~800' deep); I have an unknown but reasonably fixed (artesian) pressure at the pipe inlet; I can only measure pressure at the pipe outlet; ...
0
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2answers
37 views

Is the force exerted by the container on the fluid and the force exerted by the liquid on the container equal?

I came across a question where i was asked to find the force exerted by the walls of a frustum shaped bucket on a liquid inside it . I found the force exerted by the liquid on the walls of the bucket ...
1
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1answer
42 views

What happens to the level of water when ice containing stone melts? [closed]

What would happen to the level of water in a vessel, when ice containing a stone, melts? If there was no stone, the level of water will not change. But when the ice contains a stone inside it ...
-1
votes
1answer
36 views

Relation between Upthrust and Newtons Law [closed]

Using Newton's $2nd$ law of motion, show that when an object floats on the surface of water, the upthrust experienced by the object and the weight of object must be equal? The first thing is I don't ...
1
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0answers
25 views

Calculation of water pressure [closed]

I have a water tank of 750Ltr capacity installed at a height of 7.5M from ground. How to determine the range of pressure gauge required to measure the pressure from ground level.
0
votes
1answer
20k views

To calculate pressure at point in a vertical water pipe of given diameter

Is it possible to calculate pressure at a point in a pipe, where a solenoid valve shall be placed, given that the pipe carries water (utility supplied, regular water) from an overhead tank (at a ...
2
votes
2answers
115 views

Water bombing - risks and possibilities

I just saw a video on youtube, where an excavator drops a load of water on a car, destroying it completely. I also saw a video with a fire-fighting plane dropping even more water on a burning truck. I ...
1
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0answers
26 views

Fluid mechanics [closed]

While solving questions from the past years papers of iit jee i came across this question Two identical cylindrical vessels with their bases at the same level, each contain a liquid of density ...
0
votes
1answer
23 views

I need to know the pressure of gravity feed elevated water tank [closed]

I have a rain catchment tank holding 5,600 gallons of water 7 feet above the ground. I want to run this water 20 to 30 feet to drip water plants. Currently a hose runs to a computer valve (timer) ...
1
vote
0answers
48 views

Melting of ice in beaker [closed]

If we have (i) ice with a stone frozen and (i) ice with a wood frozen . Both of these are kept in a beaker full of water . Then what will be the the change in water level in both cases when stone has ...
0
votes
1answer
32 views

Difference of water pressure

We know that $P = \rho gh$, so is it true that water pressure at 2nd floor will be higher than water pressure at 9th floor of a 12 story building?
0
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1answer
39 views

What does Low Surface Tension mean?

I have that a book that says "Low surface tension of a liquid helps it to spread over a larger area." . My question is How and Why ? When I say that a liquid A has a lower surface tension than liquid ...
33
votes
4answers
4k views

What is the energy source if a tall water tank is used to transfer floating objects upwards instead of cables with motors?

Suppose I want to transport some logs from the ground to the roof of a tower. Originally I can use a lift, or some cables, or even move the logs upwards manually; then the energy is converted to the ...
1
vote
2answers
120 views

About the real reason why paper doesn't fall in HALF-FILLED inverted cup [duplicate]

I just happen to see a show about air pressure host by Brian Cox. As the link:http://imgur.com/EsRadFi shows, he flipped a half-filled water cup upside down then the paper on cup doesn't drop: It ...
3
votes
2answers
79 views

Pressure change when closing valve inside a column of water

Main question: If you have a column of fluid with a valve as shown on the drawing, what happens to the pressure at the point p when moving from state A to state B ...
14
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7answers
1k views

How to keep a helium balloon between 1 to 5 meters above ground? (without it being tied)

I understand that helium balloons rise because their density is less than air, so they can rise up to a point where the air surrounding it has the same weight as the balloon. I was thinking to fill it ...
1
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1answer
114 views

Metallic coin over wooden block in glass of water

So there is some water inside a container; the height of water inside the container is $l$. I placed a wooden block on the water and it's floating to some height $x$, on top of the block is a metallic ...
2
votes
2answers
106 views

Why doesn't the air in a Standard Diving Dress crush you?

I recently watched a Mythbusters episode where they tested decompression in a tethered diving suit (which I believe is a Standard Diving Dress). When they removed the air pressure, the suit crumpled ...
3
votes
2answers
372 views

Why closed bottle change its weight when I put effervescence tablet?

I use several shape, several type of material (glass, metal, plastic), I use two different balances with 0.01g of accuracy. I put oil on gasket, and put upside down (like that I can see if water ...
0
votes
1answer
42 views

why don't we consider atmospheric pressure or weight of liquid while deriving the equation of thrust in a fluid?

More specifically , when we try and prove that up thrust experienced by an liquid column inside the liquid is equal to the weight of the liquid column , I have seen it being derived like this: thrust ...
0
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2answers
44 views

Is Buoyant force a reaction?

When we fall on water. The surface molecules are pushed down and as a consequence molecules below the surface molecules and molecules beneath them and so on are also pushed down. Some of them are ...
2
votes
1answer
95 views

How does hydraulic press work at molecular level?

Let's consider the following arrangement: I know that because of conservation of energy the force on the car has to be amplified. The work $W$ done is $$W = \text{Force} \cdot \text{distance} \, ...
0
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0answers
27 views

Liquid pressure confusion

Water molecules are free to move around and they collide with the walls of the container in which they are kept.So,as a result they should exert pressure on the walls.But, while calculating force ...
0
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1answer
42 views

Doubt in the concept of Upthrust and Buoyancy

First of all, we know that $P = hρg$ for any depth h in a liquid. While deriving this formula we use (mg + P1A) - P2A = 0, where P1 and P2 are pressures on the upper and lower surfaces respectively. ...
13
votes
4answers
251 views

How quickly should a fluid come to hydrostatic equilibrium?

Let's say I'm holding a one-liter water bottle, full of water, which I then drop. Before dropping the water bottle, the equilibrium is for there to be a pressure gradient in the water canceling the ...
4
votes
2answers
117 views

Why do helium balloons rise and fall?

I understand why a regular party balloon filled with helium falls over time due to leakage of the helium. However I've also noticed that recently filled helium balloons put outside rise and fall. At ...
8
votes
3answers
11k views

Why does the water level equalize in a series of tubes?

Say I have a series of tubes (not the internet) looking like this, where w represents water: ...
1
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1answer
34 views

Flotation of a body which is submersed into a incompressible fluid using Archimedes principal [duplicate]

There is a small boat in a water tank and the boat is loaded with a huge piece of rock .The water tank is totally filled with water .If the rock is taken off from the boat and totally submerged in the ...
0
votes
1answer
51 views

The Direction of Pressure Gradient in Hydrostatic Equilibrium

The equation for Hydrostatic Equlibrium in galaxies and galaxy clusters is quoted as: $$\frac{dP}{dr}\times\frac{1}{\rho} = -\frac{GM}{r^2}$$The minus sign on the right hand side indicates that the ...
0
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2answers
43 views

Finding the work done to fill the tank by pumping water over the edge? [closed]

I am really confused on how to approach the following question and how to set it up. So the question is: An open tank has the shape of a frustrum of a right circular cone. The tank is ...
4
votes
3answers
561 views

How can the atmospheric pressure be different in distinct points at the same altitude?

From an hydrostatic point of view, the pressure in a fluid should be the same at the same depth/altitude. Obviously, in our atmosphere that does not happen. I am guessing that the main reason is the ...
3
votes
2answers
118 views

Why buoyancy is applied on centroid?

My book says: "The point of application of the buoyancy force is the geometric center(centroid) of the submerged part of the body, whereas the specific gravity of the fluid is constant." But why ...
1
vote
1answer
128 views

Questions on Pascal's Principle

I am aware that Pascal's principle says that if a pressure acts on an enclosed liquid, the pressure will be transmitted uniformly throughout the liquid. Can Pascal's Principle be applied to a ...
-1
votes
1answer
49 views

A pure water ice cube with sides 2cm long floats in a liquid in a glass beaker [duplicate]

A pure water ice cube with sides $2\,\mathrm{cm}$ long floats in a liquid in a glass beaker. What volume will be below the liquid surface if the liquid is a) pure water and b) brine? ...
0
votes
1answer
55 views

Could a big enough straw stretching from Earth to space eject atmosphere into space? [duplicate]

Assuming the straw can be built out of any material, shape, size. Would the vacuum effect of space acting on the pressurized gas have enough force to lift the weight of the atmosphere contained in ...
21
votes
4answers
4k views

Why does a cork float to the side of a glass?

What is this physical phenomenon and when it's happen ? Please take a look at this picture: Notice: This is a cork ball attracted to sides of a glass of water
6
votes
2answers
457 views

How come a cork float to the side of a glass? [duplicate]

There's a not-so-recent video by a user named quirkology here, where he shows bets that usually work. From @2:19, he puts a wine bottle cap at the center of a glass ...
0
votes
1answer
114 views

Would a pipe from the surface to the Earth's exosphere suck all atmosphere to the space? [closed]

If I built a tube from Earth's surface to the exosphere, would all the air be sucked out to space? If this pipe reached to a big planet, like Jupiter, would its gravity through the pipe suck our ...
5
votes
1answer
153 views

Hydrostatic forces in a bowl of cereal [duplicate]

This morning I was eating cereal which consisted of roughly spherical pieces just shy of one centimeter in diameter. By the time I was nearly finished, the cereal pieces were floating in a monolayer ...
0
votes
1answer
37 views

Fluid pressure when it is not vertically placed

The pressure of a point in a fluid is the sum of the external pressure and $pgh$. However, when the fluid is not placed perpendicular to the ground, then what is $h$ here? For example, a cup of water ...