# pressure's questions - Chinese 1answer

1.725 pressure questions.

### 1 Does a higher water volume increase pressure?

4 answers, 3.962 views newtonian-gravity pressure hydrostatics
I am constructing a gravity flow water system. I have 100ft point where I can put my tank. My question is does the size of my tank matter? I am using a 1" pipe. Will I get more pressure if I use a ...

### -3 The Mystery of the Starbucks coffee lid [on hold]

1 answers, 74 views pressure everyday-life
If you look at a (white, opaque) Starbucks coffee lid (and the lids of many other coffee brands as well) you will see in addition to the obvious sip hole, one or more tiny perforated holes on the top ...

### 2 How does the vertical distance beneath the surface of a fluid create pressure? (thought problem)

4 answers, 386 views pressure hydrostatics
Specifically, I am trying to wrap my head around this scenario but can't do so solely by thinking about the weight of the fluid. Imagine a perfectly still lake. If you dive into the lake, the ...

### Can gas at near-vacuum densities pool at the bottom of containers?

1 answers, 28 views gravity pressure vacuum density gas
Ordinarily, we assume that a gas expands to fill it's container, however, I've had the thought that at low enough densities, this may not be possible, because the force from pressure would not be ...

### -2 gas escaping a tank through a hole [duplicate]

i have a tank filled with n moles of gas with a greater pressure than the atmospheric. the pressure difference is deltap. there is a hole with surface s and the gas flows out of it.the temperature is ...

### 1 Thermodynamics Work Done At constant pressure and charles law

1 answers, 936 views thermodynamics pressure ideal-gas
If we fix a piston in the mouth of a cylindrical container in such a way that the piston settles when the pressure from outside the piston is equal to that of the gas within the container, and ...

### 1 Hydrostatic pressure in regards to a submersible vehicle

1 answers, 19 views pressure fluid-statics
For many years I have wondered about the physics in a scene from the James Cameron movie, "The Abyss", where a submersible sinks because of small leaks caused by a crash. In this scene, Ed Harris' ...

### 2 Density solver for ideal mixture of real gases

1 answers, 285 views thermodynamics pressure density
I am referring the paper on GERG-2008 equation of state. I am interested in calculating the properties of ideal mixtures of real gases. The GERG-2008 EOS is in Helmholtz free energy and hence the ...

### How do scientists measure vapor pressure?

Experiment: We have a cylinder with a piston that is essentially weightless, frictionless, and exposed to atmospheric pressure. The cylinder has a volume of 2V, but half of it is filled with water and ...

### 1 Flow rate of gas down a pipe at low pressures

1 answers, 635 views pressure ideal-gas kinetic-theory gas

### Above-the-ground pool slope pressure calculation

1 answers, 24 views classical-mechanics pressure water
I'm not sure this is the right place to ask this "homework" question, but I have a real life problem that requires calculation and I do not have the math knowledge to make them myself. I have bought ...

### Explanation for concept of Relative Density

I am in class $9^{th}$, I'm reading my physics book in which it is written that: \mathrm{Relative\ Density} = \frac{\mathrm{Weight\ of\ solid\ in\ air}}{\mathrm{Loss\ of\ weight\ of\ solid\ in\ ...

### 1 Using compressor as vacuum pump [on hold]

1 answers, 51 views pressure vacuum
Why is it that a typical auto-shop compressor can easily fill big truck tires to +80 psi, but when used as a vacuum pump the same motor/valves can typically only pull -12psi or so of vacuum?

### Aircraft propellers generate positive and negative air pressures (air before and after the prop). How much and How far in front?

Picture this: A small airplane parked in a field, running at full power, developing 2,500 pounds of thrust from the single propeller. (A drawing would really help, but I'm new to this forum and don't ...

### Total and static pressure: which one is measured?

Which pressure is measure using measuring device in a pipe flow. My first intuition that it is the static pressure. This is confirmed by this Wikipedia article (link) The concepts of total ...

### How can I derive the virial stress from the maxwell stress or vice versa

0 answers, 24 views electrostatics pressure stress-strain

### 2 Balloons and lifting gases

4 answers, 6.036 views forces pressure buoyancy faq
Hydrogen is the lightest element, so it's cable of lifting the most weight in out atmosphere (probably not the best terminology there, but you get the picture) Would hot hydrogen (in the same sense ...

### 8 Why water in the sink follow a curved path?

When you fill the sink with water and then allow the water to be drained, the water forms a vortex.. And then it starts to follow a curved path downwards by effects of gravity. Why this phenomena ...

### 2 Why aren't canal locks nearly impossible to open?

0 answers, 40 views forces pressure water
So I've just been watching a TV program where two people open a canal lock, and it occurred to me: aren't you pushing against the entire pressure of the river when you push the lock doors open? Why is ...

### 3 What is water pressure, really? [duplicate]

It's easy for me to imagine gas pressure on a molecular level. More pressure means that more molecule bounce against the thing you are measuring, or the molecules hit it with more speed or the ...

### Pressure under water considering bulk modulus

I want to calculate the under water pressure, taking into account the compression of water. I derived a formula, but apparently the function has a vertical asymptote, meaning that the pressure ...

### Pressure exerted by CO2 gas vs N2O in 0.5l container

What pressure is exerted by 8g (eight grams) of N2O gas on the walls of a container that has about 0.5l (half of liter) of volume? Will the pressure be the same in case of 8g of CO2 gas? Background: ...

### -2 how to get high humidity and low temperature in room [closed]

1 answers, 29 views pressure water sun air
I want to start mushroom farm for that I have to maintain high humidity and low temperature for that ,So i finding solution for how to get high humidity and low temperature at low cost.

### 4 Second derivative of vapor pressure from a cubic equation of state

It is quite easy to compute the first derivative of vapor pressure with respect to temperature from a cubic equation of state at least at the critical point since there is a continuity with the ...

### 2 Is it possible to create a soap bubble in space?

1 answers, 61 views pressure vacuum surface-tension bubble
since space does not contain air, is it possible to create a soap bubble without air in space or in vacuum and can can you explain why so? OR will there be any possibilities for a bubble in such kind ...

### 1 What is the explanation of Pascal's law at molecular level?

1 answers, 217 views pressure fluid-statics
What is the molecular explanation of Pascal's law? Let us now consider what happens when we change the pressure on a fluid contained in a vessel. Consider a horizontal cylinder with a piston and ...

### Determine fan sound (dB) based on its rotational speed (RPM)

I am trying to find the sound amplitude or level produced by a fan, knowing its RPM. Is there a simple formula for it? What other parameters does it depend on? Assume I have all the fan properties, ...