Force per unit area.

learn more… | top users | synonyms

-1
votes
2answers
45 views

Would a person gain or lose weight after expelling a flatus?

Considering the chemical composition, mass, and pressure range of typical human flatulence, would a person gain or lose weight after passing gas?
1
vote
0answers
18 views

How do I calculate the maximum pressure a container can withhold?

Say I have a spherical container with a certain gas inside, heated to a very high temperature, and thus a very high pressure. The gas will exert a force radially outwards onto the container, and at ...
0
votes
3answers
37 views

Pressure change with a pipe diameter change

I have a question regarding a water line from the street to a house. What happens to the pressure in a water line if it goes from a 1" diameter pipe (at street) and increases to a 1.5" diameter pipe ...
1
vote
2answers
46 views

Atmospheric pressure on a flat object

Consider a 10 inch by 10 inch sheet of paper lying flat on the ground. If atmospheric pressure is 15 pounds per square inch (sea level), then there is 1500 pounds of force acting downwards on the ...
0
votes
0answers
23 views

Tripple point for water? What other molecules? [closed]

What other modules have a triple point?
-1
votes
1answer
46 views

How long will pressure exist in this case?

I'm currently fabricating my project, which currently exists only on paper, and there's one question to which I have stumbled today. Suppose, that I have a pressure vessel capable of holding upto ...
0
votes
3answers
55 views

Does a gas in a container lose kinetic energy?

When a gas is in a container, it frequently collides with the container wall, exerting pressure. However, with a collision, kinetic energy ought to be transferred from the gas molecule to the ...
-1
votes
2answers
51 views

If you place a filled water bottle at the bottom of the Mariana Trench, how does the bottle stand the enormous pressure?

The pressures are akin to an entire train pressing down on you. How does the water bottle stand this pressure? And yes, the water bottle will stand: How else do the creatures at the very bottom of ...
0
votes
1answer
18 views

If you brought a hollow one-inch cube of steel filled with air into space, would the air exert a pressure of 14.7 psi on the cube?

In my thought experiment, since air exerts $14.7$ psi at sea level, the air within the cube of steel should exert the same pressure outward, $14.7$ psi. Right? The whole thing about balanced air ...
0
votes
0answers
11 views

What happens if you blow at a paper wad sitting at the doorway of an airtight room?

Sounds like a hilarious scenario, but this is why it got me thinking: A common experiment demonstrating air pressure is to put a paper wad at the mouth of a bottle, and then blow into the bottle. The ...
6
votes
1answer
705 views

Could a vacuum airship be possible? [duplicate]

According to Wikipedia, a vacuum airship is a hypothetical airship that is evacuated instead of using a lighter gas. Really, once I first saw this, I thought, "Why did I never think about this ...
0
votes
0answers
19 views

Pressure gradient - derivation for air stream

I need help clarifying the statement made here that $$dp = l\frac{dp}{dx}$$ $\frac{dp}{dx}$ is an infinitely small change in pressure at some point x. $dp$ is the total change in pressure between ...
-1
votes
2answers
51 views

How do I calculate the weight that PSI can lift?

Imagine that there's a force that is given to you in $psi$, say $1450\ psi$. And there's some body of weight say, $100\ kg$. What I want to know is that, how much $psi$ will I need to lift the "body" ...
-1
votes
1answer
20 views

what is the pressure that a sonic wave actually creates?

We know that sonic waves across atmosphere are basically areas of high and low pressure. But I couldn't find how much is that pressure. There are online calculators to calculate the sound pressure, ...
0
votes
0answers
20 views

What happens when heating water in a pressure vessel?

Suppose that I take a pressure vessel that can hold up to 2000PSI force. Now I fill it with water (not completely, but around ~90%) and now I start to heat it with direct flame, LPG gas cylinder. What ...
0
votes
2answers
34 views

what is the effect of a sound wave at the opposite side of its direction?

We know that a sound source produces a sound wave and a high pressure area is followed by a low pressure area, while they travel with 300m/s. My question is, if the sound source travels with 50m/s in ...
-1
votes
0answers
12 views

Tapering Mercury Barometer

I am curious if the height of the Mercury column inside a Toricellian Mercury Barometer be the same if we use a tapering / stepped (unequal inner diameter [ID]) glass tube as depicted in the image ...
0
votes
0answers
15 views

Slow sustained liquid movement in a vacuum

Can water or any other liquid be made to “simmer” or “low boil” (slow sustained liquid movement) in a vacuum as opposed to go from liquid to all out boil when the vapor pressure is equal to the ...
0
votes
0answers
18 views

sound waves and atmospheric pressure

Is it possible to use sound waves (ultrasound/infrasound or whatever) in order to make some space have lower atmospheric pressure? Or maybe another way to achieve this? I was thinking that maybe sound ...
1
vote
0answers
25 views

Connection between gas flow rate and diameter of tubing

First time poster, long time troller and curious student. I have a bit of a conundrum that I would love some input on... Here's the problem. I have an air flow system is under constant pressure of ...
1
vote
1answer
48 views

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, ...
0
votes
1answer
28 views

Question about pistons and how their volume is affected by particles?

I can't find an answer to this anywhere. When pressure is maintained in a piston and an ideal gas is injected into it (again, with no change in pressure as it is injected) the piston is displaced ...
0
votes
0answers
16 views

is there any element or material that ionized when pressure is applied to it?

I want to know if there is any material, that produce free electrons and ions when it undergoes to high pressure.
1
vote
3answers
47 views

Calculate pressure with the ideal gas law or $\rho gh$?

In a container the pressure on the walls due to a gas can be calculated using the ideal gas law $\bigl(pV=NRT\bigr)$. However, for a column of water, or the pressure at earth's surface due to a ...
0
votes
0answers
17 views

Is surface tension the result of a pressure drop over the air-water interface or visa versa, for a two sphere system?

For a liquid bridge between two spheres the Young-Laplace equation states that: $\vartriangle p= \gamma\bigl(\frac{1}{R_1}+\frac{1}{R_2}\bigr)$ where $\vartriangle p$ is the capillary pressure ...
1
vote
2answers
48 views

Is this a case of the “venturi effect”? What's behind the “Venturi effect” actually?

Some dinghy sailboats have a hole in the bottom of their deck used to automatically bail out water after a capsize. bailer of the laser sailoat The mechanism only works if the boat is moving. The ...
2
votes
1answer
74 views

Will changing the pipe diameter reduce the pressure head loss?

I have this system installed in my house (fig 1), and I'm having problems with the shower. I want to know whether, if I change the PEX tubes shown in red from 1/2" to 1" as shown in fig 2, I will have ...
14
votes
9answers
4k views

How to emulate 40ft (12 m) of water? [closed]

I am part of an underwater robotics team, and our next year's challenge requires us to compete at a depth of 40ft. We don't have any pools nearby to test in, so I want to emulate this 40ft of pressure ...
0
votes
1answer
27 views

Is 0.1 bar (hydrostatic pressure) equivalent to 0.1 bar vacuum pressure (absolute pressure)?

Suppose we would like to test the ability of an objec to withstand the pressure under 1 meter of whater. I would like to understand how to simulate this situation using vacuum. Is the 0.1 bar (for 1 ...
12
votes
4answers
2k views

Are there limits for the speed of sound? A maximum or a minimum only?

The speed of sound in materials of various states of matter differs a lot. But does it have fundamental limits? Is there a maximal possible speed of sound? Is there a minimal possible speed of ...
0
votes
0answers
15 views

Density and pressure of the earth core [duplicate]

According to some sources the density of the earth core is about 9.5kg / m^3 and the pressure: 4*10^11 Pa I know the gravitational force decreases, if you get closer the center of the earth, ...
0
votes
1answer
39 views

Few doubts about saturated vapour pressure and unsaturated vapour pressure

I have some sort of confusions towards saturated vapour pressure and unsaturated vapour pressure.. So let me give you those. What is exactly saturated vapour pressure and unsaturated vapour ...
0
votes
1answer
46 views

Pressure - How much fluid can void support?

Please refer to the attached (terrible) drawing while reading the post ! After watching some videos about the U-tube effect in drilling, a question came to me. Imagine one fluid of heavy density ...
0
votes
2answers
35 views

Does atmospheric pressure have a net contribution to this FBD (free body diagram)?

Pressure acting on the left and right sides of the block counteract
3
votes
4answers
1k views

Water pressure on a floodlight in a swimming pool [closed]

I have a circular swimming pool with a diameter of $4.5\;\text{m}$. The water height usually is about 1m. Somewhere in this pool is a single floodlight, circular aswell, diameter $25\;\text{cm}$. I ...
3
votes
1answer
55 views

Forces of suction in WIllie Wonka's Chocolate Factory (filmed 2005 starring Johnny Depp) [closed]

Before I begin the question: I am in no way judging this movie, just happened to be casually watching it and saw the scene (referred to below) and thought to post this question. The scene: Boy falls ...
1
vote
0answers
28 views

Measuring variation of saturated vapour pressure with temperature

Is it possible to measure variation of saturated vapour pressure of water with time.I just hesitate about it.My suggested procedure which is incomplete is given below Procedure that I would like to ...
0
votes
1answer
29 views

Pressure and humidity

Does pressure/vacuum affect water vapor differently than other gases and hence humidity? For example, imagine I have a vacuum bell at atmospheric (mean sea level) pressure and the air in it is 50% ...
1
vote
3answers
46 views

Direction of pressure forces on a control volume (surface)

According to http://www.mne.psu.edu/cimbala/Learning/Fluid/Pressure/pressure_basics.htm, "Pressure always acts inward normal to any surface (even imaginary surfaces as in a control volume).". ...
0
votes
1answer
53 views

What is dP in pressure?

I'm reading a textbook, chapter entitled "Fluid Mechanics". This section is entirely devoted to fluid statics. Assuming an element of fluid in equilibrium, Consider a thin element of fluid with ...
0
votes
0answers
16 views

What is an isostatic gas?

I'm learning about Hot Isostatic Pressing (HIP), but I don't understand what an isostatic gas is. Can someone help me?
16
votes
3answers
427 views

Swimming in a ball of water in space

What would I feel if I went swimming in a ball of water in space? Would I feel greater pressure as I went deeper into the sphere? What would it be like to swim in something like that? Also, let's say ...
2
votes
1answer
37 views

How does an airlock depressurization damage a docking vessel in space?

Can someone explain the science behind this? also i feel like in movies the ship always crumples inward, but shouldn't the only force at work be the pressure from the molecules of air in one connected ...
1
vote
2answers
46 views

unchanged temperature of balloon inside freezer

I'd tried to put a balloon in the freezer and after enough time (several hours), I took it out and noticed that as I touch it that it's temperature did not drop down . I took an empty balloon ( not ...
1
vote
0answers
39 views

Impact Force/Pressure of a wave on a vertical wall given PIV velocity field

I have PIV (Particle Image Velocimetry) data of liquid sloshing on a rectangular tank which produces a wave impacting one of the vertical walls. In the picture below you can see the wave about to hit ...
0
votes
0answers
16 views

The pressure profile of a static heap of granular substances

The following is the pressure profile of a pile of sand. Note that there is a pressure minimum at the center. A possible explanation for this is: Due to the close packing of the grains, any grain ...
0
votes
1answer
39 views

What is the pressure at this height? [closed]

The height of a mercury barometer is h when the atmospheric pressure is 100,000 Pa. At height h/5, what is the pressure? The choices given are 20,000 80,000 120,000 180,000 The answer given is: ...
1
vote
2answers
82 views

Can pressure be negative? [duplicate]

From Wiki and from physics fundamentals lections I received info that pressure is scalar value. But in definition you have relation between projections of two vector values to normal axe-force and ...
-1
votes
2answers
53 views

If pressure inside a container is lesser than atmospheric pressure, how long can the vessel resist deformation? [closed]

Is the strain caused by stress (due to the pressure difference) is negligible?
0
votes
3answers
68 views

Why do our ears pop?

Have you ever been on a train going through a tunnel or plane and your ears pop?I was wondering why this happens and I know it relates to pressure but don't know exactly the reason