Force per unit area.
2
votes
2answers
65 views
Intuition contradicting answer for calculating pressure
I have a cylindrical container say of some base area $A$. The atmospheric pressure is $P_0$. The cylinder is moved at an acceleration $a$ horizontally right. I need to find which base would have to ...
1
vote
2answers
158 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 ...
-1
votes
2answers
149 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, ...
5
votes
1answer
74 views
What if the lid of a pressure cooker was suddenly released?
My dad and I have tried to calculate the strength of the explosion if the lid was suddenly freed. We took some measures:
Lid mass: $0.7 \textrm{kg}$
Lid surface: $0.415 \textrm{m}^2$
Internal ...
2
votes
1answer
48 views
Is this the correct way to I combine multiple interdependant pressure readings?
I want to measure the density in different layers of a suspension. To do this I want to place pressure sensors at different heights. Let's assume that the sensors are not by orders of magnitude more ...
1
vote
1answer
44 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
1answer
56 views
Calculating Air Density Lapse With Altitude (Specifically, pressures)
This might be a bit more of an engineering question, but I'm calculating air density drop-off with altitude, and I'm having some problems calculating the pressure (I'll run through my method). This ...
1
vote
1answer
141 views
How should holes in a Tesla turbine look like?
I think of building a Tesla turbine out of old hard drives.
Now I wonder how to cut ventilation holes in the platters.
On the internet there are a lot of different attempts on that matter. A lot of ...
1
vote
1answer
114 views
What happens to the vapor pressure when I expel the liquid phase from the vessel?
Suppose I put water in a closed vessel and heat it, so the vessel becomes pressurized above ambient pressure. Now, there should be liquid and gaseous water inside the vessel. Since it's under ...
1
vote
1answer
59 views
How to calculate the amout of time for oil to get out from a pneumatic cylinder?
I have a system. You can assume it is just a 1" diameter steel pneumatic cylinder (1 foot long). Assume we ignore the bore size issue at this point. One chamber is filled up by oil (6" of volume), ...
0
votes
1answer
41 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 ...
-2
votes
1answer
184 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 ...
4
votes
0answers
776 views
Inflating a balloon (expansion resistance)
I am doing a quick calculation on how to calculate the pressure needed to inflate a perfectly spherical balloon to a certain volume, however I have difficulties with the fact that the balloon (rubber) ...
2
votes
0answers
91 views
Internal moment in the hull of a pressure vessel
This question is related to the course structural analysis. As part of our exam grade every student has been given different multiple homework assignments which we have to solve.
One of the problems ...
1
vote
0answers
43 views
How to solve state parameters using these givens for an ideal gas?
In a thermodynamic turbine using air as an ideal gas, given that you have a known inlet temperature value $T_i$, a known exit pressure value $P_e$, a known inlet and exit velocity $V_i$ and $V_e$, a ...
1
vote
0answers
29 views
pressure required for displacing a single electron off a crystal
I need to know this for my project- "power generation using the pressure applied on a keypad of a mobile electronic device". How much pressure does it take to displace a single electron off its ...
1
vote
0answers
41 views
How do I calculate the energy balance of a trompe?
I was quite fascinated by the concept of an ancient type of air compressor, called a trompe. It entrains air bubbles into a falling stream of water via the Venturi effect, and extracts the air at a ...
1
vote
0answers
35 views
Can I use computer fans and tubes to lower the air temperature below dew point?
I suppose to build a small dehumidifier, but I am narrowing the question down into its logics.
I have relatively powerful computer fans, water cooling radiator and some metal tubings. With the idea ...
1
vote
0answers
53 views
Determining Water Level
Given a cylinder of a constant shape and size, how can the water level be calculated using the inside surface of the container?
For instance, could the inside lining of the container be a pressure ...
0
votes
0answers
52 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
21 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
17 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
23 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
0answers
142 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
203 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
138 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
91 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
284 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, ...
