Air Definition and 1000 Threads

I know there are many factors that affect this question, such as altitude etc, but in its simplest form... - How fast does a parcel of air rise if, say, the parcel of air is at 5 degrees centigrade in a room filled with air at 0 degrees C. (Maybe I should be using Kelvin?). Just need to get an...

Hi guys, I came upon a definition of Non Newtonian fluid that is any fluid which doesn't deform linearly with increasing stress. But then if you think about fluids, pretty much every fluid acts like this, depending on whether you're actually capable of generating enough force to see it happen...

Homework Statement 1.Since the roadster seats only two people, it has only two side windows--one on each side. Each window is aligned squarely on the vehicle, so air can flow straight past the window as the vehicle heads forward. However, the air flowing around the roadster's windshield has to...

Lets say you have a jar of water, and a jar of air. You heat both of them 100C will either of them explode? ok just kidding. which one exerts more pressure, and is hence more likely to explode? did heating the substance turn heat into force? (force per unit area)

Homework Statement [/B] Hi everyone! So I've got this similar problem as I posted yesterday, but this one is slightly different due to the presence of gravity: A particle in gravitational field ##~~g## starts traveling upward (positive direction) along the y-axis from ##~~y=0## with the...

I am planning on making an experiment about intersecting continuous wave laser from 2 or more source on 1 point in thin air. The laser i am planning to use is the simple laser diode, pumped with continuous wave, instead of using pulsed wave as in the usual laser pointer as i don't need it to...

Hello Homework Statement Lets say i have the given parameters: air volume flow : V = 36 m3/h Relative humidity: RH=33% air mixing ratio : X = 5.5 (1g H2O) / 1kg (DRY AIR) (calculated from RH) air temperature : T= 20 C So i know how much mass of water is the air compared to the air's "dry air"...

Hello, It is well known that the atmospheric air pressure is significantly strong but our body does not get crushed by it because and equal pressure pushes from the inside our body. That said, does it mean that air can exist and be diffused inside solid organs like the lungs, our heart, etc...

Why we assume total air pressure (dry air +water vapour) to be constant during study of properties of moist air even when it is being heated or cooled how it is possible that pressure is constant , on what basis it is assumed? I think locally there must be variation in total pressure also due...

Why drag force doesn't Depend on the mass of the Object?

Hi! I was wondering how I could come up with a differential equation for projectile motion on a 2D plane when air resistance is not negligible. I'm trying to guess the position of a projected ball at a certain time period by approximating the coordinates using the Euler's method. Here, I would...

Stupid question: I have the following pipe configuration: Working fluid = ambient air Pipe1 = 6 inch ID x 24 inch length Expansion1 = 2 inch length Pipe2 = 8 inch ID x 2 inch length Fan1 = assume 200 CFM @ 2860 rpm, 0.05 inH2O Contraction1 = 2 inch length Pipe3 = 6 inch ID x 12 inch length...

Homework Statement [/B] I know only the length (l) and cross-section area (S) of an air tank, cylinder. The question is how much work is needed to pump out air from the cylinder. Homework EquationsThe Attempt at a Solution Is it correct to use here the formula W = pV? The initial pressure...

Air is flowing through a pipe, through a heater matrix. Flow, Inlet temperature and heater power vary. Is it possible to calculate the heat capacity of the matrix by using the Inlet & outlet temperatures, power & flow? I'm assuming no heat loss to the pipe walls to make it easier, but I'm not...

Hi I am trying to understand the figure 2 I have attached to this post. From text: Ok, I get that the air-gap flux density varies in a sinusoidal manner, because the air gap length is not constant i.e. non-constant reluctance and hence non-constant magnetic flux density. What I do not...

This started out as a thought experiment and then I realized I was stuck in how to figure it out. If I have an airsoft rifle that uses compressed air in the tank at 3000 psi. It leaves the bottle regulated down to 800 psi. It then goes into a second regulator that reduces the pressure further...

Could anyone please let me know if breakthrough spark can happen, or, in general, what will happen in the below system? Note 1: the dielectric layers have a much higher breakthrough voltage than humid air. Note 2: the intensity of the electric field that develops in the flow of the humid air is...

Hi there, i am struggling with the following problem. Air is pumping into a bottle with volume V and pressure Pi until it reaches a final pressure Pf. The temperature remains the same during the process and the gas is an ideal one. We have to calculate the work that is done. I am not quite...

I've been trying to read up and understand why a air burst of a nuclear weapon is less catastrophic than a ground burst when speaking about nuclear fallout. I think I understand that intensity of the dangerous radiation falls off quickly because of an inverse square law, but what happens to the...

Hello, I have a Coen Duct burner system that requires a continuous flow of 120 scfm @ 5psi above duct pressure. Duct pressure is about 3 inwc. We have 6 pilots that will have a 1/2" inlet for the air. Our plant air system can supply 120psig and about 400 scfm. My issue is figuring out what...

Homework Statement A hot air balloon is released from the ground & rises up with a constant acceleration of 4 m/s^2. When it is 16 meters above a sandbag is dropped. What is the time taken for the sandbag to hit the ground? Homework Equations v^2=u^2+2as v=u+atThe Attempt at a Solution...

Hi all, My name is Jesse and I love renewable energy and finding ways of beating coal. Right now Solar Photovoltaic energy competes with coal in sunny areas during the day, but at night, you need to store the energy from solar and it's not worth it due to the cost of storage mechanisms (might...

I have a work related question. Although it seems like a relatively simple question, I am having difficulties finding the correct equation(s) to calculate the answer. Question: Given a fixed volume air tank filled with pressurized air, how does one calculate the flow rate over time through...

This seems simple, but I have some confusion. I'm trying to refine a numerical simulation to get away from my isothermal assumption, to account instead for isentropic temperature and pressure changes in pressure tank with an orifice. Given an insulating air tank of volume ##V##, containing air...

I wanted to ask. Since jets fly at great speed, often even supersonic, I'm curious about next things: 1) What is the relation between air resistance force and energy? 2) How does all that force resistance affect a pilot? 3) What protection do they have, if any? 4) And purely speculative...

If I have a closed cylinder with a fixed air volume inside and a piston on the open end I need to calculate how much the piston will move as the temperature changes through a range of 100 degrees F? Air volume vs temperature?

I am attempting to identify how long it would take to bring different volumes to a specific pressure using air compressors. I understand that the flow rate given for an air compressor will change as the outlet pressure increases, but I am having some trouble finding the equations to describe...

Hi all, I am trying to wrap my head around how much air is needed to transfer liquid from one tank to another tank. Here is a sketch of the problem The valves at the bottom of the first tank opens up, and air is transferred to the first vessel to transfer the liquid completely to the...

hello, i am trying to calculate the volume of a balloon (which is quite large). It has been filled with helium via a valve connecting helium storage tanks to the balloon. The knowns I have are the volume of the storage tanks, the intital pressure in the tanks, and the final pressure in the tanks...

Hello I'm trying to understand how exhaust systems work .In general I want to understand how air movement changes according to leight of vent tubes. Example I have made little vent system with in lane fan that sucks air out of room. As I understand air speed in tube that is pulling air from...

Hello, I am high school student working on a project to design an air cylinder, which would fire seed pellets from the drone at specific time intervals with sufficient pressure to embed them into the soft soil. I looked up on the Internet about airguns and other stuff but couldn't find...

1. Homework Statement This is my first question and I'll try to stick to the forum rules as much as possible. imgur.com/a/2JyZC Imagine a cylinder filled with air which is uniformly distributed and a piston above it, so the air can expand vertically. Let the system be the air itself, so the...

Homework Statement Air is to be compressed from a pressure of 1 bar and a temperature of 20°C to a pressure of 15 bar in a two stage compressor with intercooling. After intercooling the air temperature returns to 20°C and the polytropic index of compression is 1.28. If the input power per...

People routinely live above 4000 m, where oxygen partial pressure is under 130 mbar. True, we often suffer mountain sickness there, and take days adapting to the height as we walk up. But airplanes are only pressurized to 760 mbar total, 160 mbar oxygen. And that drop, from 210 mbar to 160 mbar...

Hello, I have a question regarding the effect of compressed air. I'm working on hydrostatic pressure testing a component. The component will be filled with water and compressed to 1000 psi. I'm concerned about the small amount of air that'll be present inside and worried about the effect in...

On airplanes - do you know of a container or bag that will stops individual bottles with liquid from leaking/ exploding from the changes in air pressure?

I know that in a closed parcel of air, if we increase temperature then pressure rises and density remains constant If we warm a parcel of air that is open i.e not enclosed, such as the atmosphere. What happens to pressure? do we say it increases or decreases? The book I have states; If the...

Homework Statement Toluene, C7H8, is burned with 30% excess air. A bad burner cause 15% of the carbon to form soot (pure C) deposited on the walls of the furnace, what is the Orsat analysis of the gases leaving the furnace?Homework Equations C7H8 + 9 O2 => 7 CO2 + 4 H2O 30% excess of air What...

Can adding a nacelle in front or behind a standard pedestal fan affect the speed of the air coming in and out? If so, which is more beneficial: an intake nacelle or a nacelle in the front? Using Q=AV, with Q being constant because of the fan blade's max speed, can affecting the area (A) create...

As most of you know real racecars have flat bottoms, rear diffusers and in the front well... a variety. So to keep this simple. I am building a car with a flat bottom and rear diffuser, car raked at 4 deg, diffuser at 14 (all details will be adjusted based on learned info) and nothing on top or...

Hi there, I'm new to this forum and this is my first post so nice to meet you all! Since English is my second language, I apologize for some odd sentences. I'm a 4th year university student and currently has an internship in a Press Shop of a car manufacturer in Thailand. The project has been...

How much air pressure, from six 1inch in diameter pipes, would it take to lift something no more then 250 pounds about six to twelve inches off the ground?P.S. This is a personal question not, homework.

Hi, I have been reading about diborane (B2H6, a gas at standard conditions) and while the sources provide different density values (!), as in 1.2475 g/L at standard conditions, or 1.18 g/L at 15ºC and 1.216 g/L at 25ºC (sounds crazy?), all of them are lower than dry or moist air at the same...

Hi, I have a question about air flow. My room is located on the corner-end of my building, on the 7th floor. I have two windows, each one facing a different side of the building, and one of the windows typically produces the breeze, and the other never does. When the door to my room is closed...

If the air resistance causes a vertical retardation of 10 percent of value of acceleration due to gravity, then the time of flight of a projectile will be decreased by nearly? Take g=10m/s^2 My attempt: Only the vertical component of the projectile will be affected by changes in g I understand...

I have been involved in a fairly furious debate about a fluid dynamics experiment regarding the pressure of air passing through a tube attached to a moving car. It is similar in concept to the issue of whether or not an opening in an aeroplane fuselage would suck people out, where the opening...

I am proposing a piece of equipment a bit similar to Crooke's radiometer with the aim of using kinetic motion of air particles to rotate the mill, without need for an external source of EM radiation. Instead of flat vanes as in Crooke's radiometer, I propose 3-dimensional vanes in the shape of...

As an airplane lover, I would like to know if a normal mobile phone (in my case a Galaxy S3 ) could recive the frequency that ATC uses, I think that is called VHF. Note: I'm sure that it isn't illegal

I have a central heat and air unit enclosed in a closet like area and it is very loud in my living room, is there a way to install a noise cancelling unit to muffle that sound of the blower unit?

Sound is vibration of air molecules knocking into each other. Intuitively, it seems the faster a molecule travels before hitting another, the faster the propagation of sound. Can't you hit air molecules harder, so the air molecules will travel faster and spend less time between collisions, and...