Force per unit area.
1
vote
1answer
43 views
How does a pierced vacuum move?
If a can of compressed air is pierced on the right, air pushes out, and the can moves to the left.
If a vacuum container is pierced on the right, which way does it move? Right? Left? Not at all? ...
1
vote
2answers
157 views
How is energy transferred from one incompressible fluid to another?
When you apply pressure to an incompressible fluid the pressure is transferred. If you stop applying the pressure there is no motion. Volume and density are integral parts of calculating how much ...
0
votes
2answers
406 views
Would weighing scales show a negative weight if placed in a vacuum?
The weighing scales in my kitchen are currently showing 0 Kg. However, there is a column of air between the scales and the ceiling that is presumably exerting pressure on them. If I were to place ...
0
votes
3answers
74 views
Lethality of sounds and extreme “loudness”
In theory, could pure sound be lethal? How loud would it have to be? Also, which events are the loudest in the universe, and how loud are they? I'm confining attention to events which occur regularly, ...
0
votes
1answer
156 views
thought experiment involving water pressure
If I were to move the syringe up, and cause it to be stationary, how does that effect the pressure at the bottom of the pipe? How does the movement of this water effect the system setup and ...
0
votes
3answers
132 views
What is the volume of a parcel of air of a giving weight at average sea level pressure
I know this is probably some basic math once you have the figures, but my Google-fu is failing me.
Say I have 5 pounds of air. Air meaning, the typical composition of the atmosphere of Earth. And by ...
0
votes
1answer
42 views
If a balloon is continuously filled with air and stays at a constant shape and size will there be any empty space in the balloon?
If a container like a balloon but with constant volume is filled, is it possible to pack air molecules so closely together that they don't have any empty space between them? If so, what would this ...
0
votes
3answers
372 views
Units of Distance, Pressure, and Temperature [closed]
I need to store data.
I'd like to store them in Metric units and use a tool to convert them to and from other units that these data points will be displayed in.
As the title states, my constraints ...
0
votes
1answer
26 views
How does a small radius connector affect gas flow?
Assume I have a 1m3 tank of air at 100 psi, they are going to release to a 1m3 tank which has air at 5 psi. There is a meter long pipe connect between two tanks.
How to calculate the flow speed ratio ...
0
votes
2answers
43 views
One Particle in a Vacuum
I recently watch a lecture by Neil Tyson where he said the closest thing we have to a vacuum is interstellar space. I believe he said there will be one atom per 1 cubic meter or something close to ...
0
votes
1answer
999 views
How much work is needed to compress a certain volume of gas?
I want to know the formula (and what does the symbols stand for) for how much work is needed to compress a certain volume of gas?
0
votes
1answer
123 views
What could I test for in a guillotine? [closed]
I'm doing a school assignment project and I need to investigate something of my choice. I was thinking of doing something about how the height and angle the blade of a guillotine is dropped from ...
0
votes
2answers
631 views
Why the pressure of atmosphere doesn't crush you when you e.g. walk outside?
Why the pressure of atmosphere doesn't crush you when you e.g. walk outside? I mean the density of air is $1.26 kg/m^3$, so with $100 km$ above us, it exerts much pressure on you when you walk ...
0
votes
2answers
349 views
What is the physical or mathematical meaning of the Gibbs-Duhem equation?
The Gibbs-Duhem equation states
$$0~=~SdT-VdP+\sum(N_i d\mu_i),$$
where $\mu$ is the chemical potential. Does it have any mathematical (about intensive parameters) or physical meaning?
0
votes
6answers
60k views
Gauge pressure vs. absolute pressure? [closed]
What are the key differences between Gauge pressure and absolute pressure?
Are there any other forms of pressure?
0
votes
1answer
2k 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 ...
0
votes
1answer
39 views
Is this a correct interpretation of pressure?
So I am told that pressure = Force per Area --> F/A..
When considering the units of Force I find that force = kg * m/s^2
When considering the units of Area I find that area = m^2
Thus the units of ...
0
votes
1answer
66 views
Real world usage; pump flow vs pressure vs pump head, what is more useful in this situation?
I am currently making a water cooling system for my computer and decided to see if I could get some better help here than what people think they know on the computer forums.
So for my cooling system ...
0
votes
2answers
77 views
Temperature change inside pressure chamber
Let's say there is a pressure chamber with some sort of sample / specimen (e.g. protein crystal) in it. Now I apply a certain amount of gas pressure, e.g. 10 or 20 atm. Let's say I use xenon as a gas. ...
0
votes
1answer
232 views
Calculate pressure of air trapped underwater
Seal top end of straw, partially submerge straw in water, how do I calculate the air pressure inside the straw?
Bonus points for compensating for any secondary factors like temp, humidity or flex of ...
0
votes
1answer
365 views
Determine the maximum height a pump can suck up water
I am working on a homework problem that presents the scenario of trying to raise water from a small reservoir of depth 8 m whose surface is 25 m below a pump that can maintain a pressure differential ...
0
votes
1answer
1k views
Ideal gas law, pressure increase and temperature
If I had a container, full with air, and I suddenly decreased the volume of the container, forcing the air into a smaller volume, will it be considered as compression, will it result in an increase in ...
0
votes
1answer
110 views
How is external pressure transmitted when a fluid is not enclosed?
Pascal's principle states that pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid.
How is the pressure transmitted in the case where the fluid is not ...
0
votes
1answer
836 views
What are the differences between the terms flammable, inflammable, and non-flammable? [closed]
This question should perhaps go in Chemistry, to which I am committed, but since the Chemistry Stack Exchange forum is not yet in beta, I am wondering if you can help me from a physics perspective.
...
0
votes
1answer
161 views
determine temperature at which pita bread will expand in a toaster
suppose you have a pita pocket of radius 5cm or .05m. We will model the pita pocket as consisting of disk with a layer of air of volume V which is contained by the surface of the bread. We will ...
0
votes
1answer
172 views
what is the relationship of sound volume to atmospheric pressure?
what is the relationship of sound volume to atmospheric pressure? if I was in a plane with a cabin pressure equal to 8000 feet would the volume drop be noticable?
0
votes
2answers
1k views
If you put a latex balloon in a vacuum, how much would it expand?
If you put a latex balloon in a vacuum, how much would it expand? And would it pop? Assume it doesn't leak.
EDIT:
Some numbers: Ambient pressure is 100 KPa, balloon is perfectly spherical with a ...
0
votes
0answers
45 views
Air pressure in balloon
I have to calculate the air pressure inside of an hot air balloon. After some searching I found out that I can use the ideal gas law: PV = nRT (from Wikipedia)
So to get the pressure in the balloon I ...
0
votes
0answers
18 views
Over-inflating weather balloons
Would it be safe to over-inflate a weather balloon if it isn't going to be used at high altitudes? I've been looking at several different balloons, but they are all measured by their burst diameter ...
0
votes
0answers
13 views
Gas Circulation [duplicate]
Dear all,
Please, is it possible to have the gas recirculated from the gas phase to the liquid as described in the diagram assuming the gas is not soluble in the water.
These are the conditions.
...
0
votes
0answers
14 views
What is the effect of an increase in pressure on latent heat of vaporization?
What is latent heat of vaporization ($L_v$) in the first place? Wikipedia seems to indicate that it is the energy used in overcoming intermolecular interactions, without taking into account at all any ...
0
votes
0answers
22 views
Formula to calculate the density of satuared steam
I need to calculate (or look-up?) the density for saturated steam in a range of 8-12 bar. Is there a formula for this? It's ok if it's not perfectly exact.
0
votes
2answers
87 views
Pascal's law: pressure of fluid at different locations
I know that's stupid question, but I'm really confused what my teachers says, so I need to check that theory.
Here are just two ordinary connected containers, which are full of water.
On grounds ...
0
votes
0answers
129 views
pressure loss in a syringe
I'm currently working on a problem which is really giving me some issues.
The problem concerns the force required to expel water from a syringe. We have a 20ml syringe (which is $2\times10^{-5}$ ...
0
votes
0answers
199 views
How much pressure is needed to break an egg if applied from top and bottom?
Everybody knows that you can't break an egg with our fingers when pushing from top and bottom.
I assume if we could squeeze hard enough the egg would break?
0
votes
0answers
135 views
What is the pressure in a vertical pipe that has moving fluid through it?
I have a system like this
When the valve is closed, pressure along any point along the thin tube may be found thru pgh. 1. What about when the valve is opened? 2. Does the top of the jar need to be ...
0
votes
0answers
87 views
Air pressure measurement - diameter of the point of measurement has affect of the reading
I am trying to measure the pressure of air flowing through the tube.
Air flow is created by a small fan with a controlled speed. I have my digital pressure gauge attached at certain point on the pipe ...
0
votes
0answers
280 views
Hydraulic System in a Simulation
A simulation project we are on, we have a machine with hydraulics that are powered (They don't just look like they move something, they are the only thing moving/turning/lifting something) - However, ...
0
votes
1answer
40 views
How does the radius and length of a pipe affect vacuum performance?
Can I use Poiseuille's equation?
Also
If I have a vacuum pump which says that its performance is 30 cubic feet per minutes and I have two pipes (one is radius R1 and L1, the other one is 2*R1 and ...
-1
votes
2answers
147 views
Fuel Tank Question
Could some one please help me with this question as my physics knowledge does not extend this far.
I have a large fuel tank with a capacity of 21000L. The tank currently is holding 2000L of fuel. On ...
-1
votes
2answers
146 views
A simple logical problem regarding pressure and force
Suppose a 2 meter long pipe, with area of cross section is $1 m^2$. The pipe is vertically placed, with the bottom end closed. Inside the pipe, at the closed bottom end, there is $1 m^3$ of air, ...
-1
votes
1answer
100 views
Liquids, atmospheric pressure [closed]
A. If a digital camera is rated as "water resistant up to 3m" how much pressure can the camera take before it starts to leak?
B. If the back of the camera has an area of 0.02 m squared how much force ...
-2
votes
1answer
183 views
For how long can we make an air balloon stay flying via remotely controlled heat system?
I wonder how a function $$f=f(h, m_{\mathrm empty}, V_{max}, T_{h}), $$ with the top height $h$, the empty mass $m$, the maximum volume $V_{max}$, and the temperature of the heater $T_{h}$ would look ...
-2
votes
2answers
153 views
Why does the higher pressure of air underneath an aeroplane wing keep it flying?
With aeroplane flight, the wings are shaped so that the air that goes over the top of the wing has to travel faster than the air that goes below the wing. This means that the air below the wing has ...
-3
votes
0answers
51 views
When do we have $p = -\frac{\partial F}{\partial V}$? [closed]
In what context can we say that :
$$p = -\frac{\partial F}{\partial V}$$
?
