# Tagged Questions

The hydrostatics tag does also apply to fluid-statics.

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### velocity of liquid in hydraulic motor

Does the speed of liquid in the hydraulic motor eye affects the revolution Per minute of the motor? So if i changed the diameter of the hose of the motor will this change any thing in the motor?
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### 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 ...
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### Could fish in plastic bags filled with water float like that?

I saw this gif earlier and it bothered me how the plastic water bags with fish in it are not submerged in water like they would if we don't do anything special with the water inside and outside the ...
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### 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 ...
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### 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 ...
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### 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 ...
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### $\nabla p=-\rho \nabla E \implies p=-\rho E +\mathrm{constant}$?

I'm not sure about the following mathematical passage. Consider the general equation of Hydrostatic in the case of conservative forces acting $$\nabla p=-\rho \nabla E \tag{1}$$ Where $p$ is pressure,...
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### 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 ...
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### The thickness of a puddled sheet of water

If I pour water of different amounts into a puddle on a level surface, it appears by eye that both puddles have the same height. The water seems to retain itself into a puddle by surface tension. I ...
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### Why the pressure in liquids only depends on the height?

look at this picture : and also look at this one: imagine that the surface area of both is the same and both of them are full of water. My question is that why they both are pressing the beneath ...
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### 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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### Is hydrostatic pressure independent of temperature?

Is hydrostatic pressure independent of temperature? Why only the weight of overlaying liquid is taken into account for calculating hydrostatic pressure and not the collision forces due to temperature?...
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### What liquid has the lowest known solubility of O2 at 20°C, 1 atm?

I have recently started a project on hydropneumatic devices, i.e. devices that use hydraulic fluids in conjunction with high pressure gases. In such systems, the most immediate thing you would want ...
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### Physical explanation of Pascalâ€™s Law

I have a problem with physical explanation of Pascalâ€™s Law. For example, when I was teaching my sister (a high school student) about force transmitting by a rope, I said her: â€œIn a very simplified ...
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### Will it sink under circumstances? [closed]

I'm a 10 year old with a question. If you have a waterproof box the shape of a prism with an open top and you have a lid that fits perfectly in the top and you fill the box with water then put the lid ...
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### Energy Conservation in Kinetic Power Plants [duplicate]

Quite recently the company Rosch has developed a new kind of power plant that supposedly utilizes the buoyancy effect to generate electricity. The apparatus consists of a vertical conveyor belt with ...
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### If a hole is drilled at the bottom of a vessel, why is the pressure of the liquid leaving the vessel equal to atmospheric pressure?

My question is similar to this one : Should the liquid come out of the tank if a hole is drilled in the vertical wall? , but I still don't understand why the pressure within a free jet of liquid/...
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### Using water pressure as pushing force in a floating bath tub? [closed]

Does physics allow for water pressure to work in this way? if so What formula can prove this? (backup link 1, backup link 2)
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### Why do we take $h$ as “height from surface to bottom” when calculating liquid pressure?

In the following image, pressures of points x, y and z are $P_{x}, P_{y}$ and $P_{z}$ respectively, and they all are equal. My question is, why? The amount of matter on x is much more than amount of ...
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### Difference between water and ethanol density for an object [closed]

I'm just slightly confused. Say that I had an object that floated 19.4m in water from the bottom of the object to the surface. Now I was going to change the fluid to ethanol, which has a density of ...
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### Pressure and altitude

I am going to ask a simple question, for sure. The pressure with respect to the altitude is given by this formula Where sea level standard atmospheric pressure p0 = 101325 Pa sea level standard ...
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### Acceleration of an bubble under the sea [duplicate]

An air bubble arises from the bottom of the sea. Find its acceleration if resistance force is proportional to $\rho Av$ where $\rho$ is density of water, $A$ is cross section area and $v$ is velocity ...
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### 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 ...
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### 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 the ...
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### 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 ...
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### 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 ...
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### 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; ...
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### 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 melts, ...
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### 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 ...
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### 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.
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### 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 ...
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### 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) ...
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### 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?
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### 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 ...
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### 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 ...