Air Definition and 1000 Threads

Hi guys, I'm doing some research in papers and literature to solve this problem but I've not found anything useful. I want to know the air velocity inside a pipe by the only effect of natural convection. I've attached a picture of the system right here: I hope you can help me to find the...

Homework Statement Ok, so I am attempting to solve a projectile motion problem involving air resistance that requires me to find the total x-distance the projectile traverses before landing again. Given: \\ m=0.7\text{kg} \\ k=0.01 \frac{\text{kg}}{\text{m}} \\ \theta=30 \degree Homework...

Homework Statement I'm currently working on the "cavendish" experiment and wish to use/develop a method separate from the casus we've been provided. Now I've nicely calculated and derived everything I need to know, including all the corrections that have to be made for the mass of the rod, the...

Homework Statement Which of the following is closest to the mean distance between air molecules at room temperature and pressure (298 K and 101325 Pa)? Assume air is made of 79% N2 and 21% O2 by moles. A 0.4 nm B 4 nm C 40 nm D 400 nm E 4 μm Homework Equations PV = nRT The Attempt at a...

Homework Statement I am trying to develop simulation for a falling object subject to air resistance. Object is similar to Samara seed. object is considered to be under steady vertical descend. know variable : surface area of object (A) weight of object (W) cd: drag coefficient object rotates...

Homework Statement A hot-air balloon stays afloat because hot air at atmospheric pressure is less dense than cooler air at the same pressure.If the volume of the balloon is 500 m3 and the surrounding air is at 60◦F. What is the maximum load (including the weight of balloon, but excluding the...

Hi all, I want to buy an air conditioning unit while they're cheap and I know you're not meant to have any windows open. I have strange windows so cannot use the fishnet attachment, long story short, if I hang the hose out of the window and just try to close the window as much as possible, will...

would an air check valve help lift by preventing air presure backup through the lift fan?

If I have a steady supply of isothermally compressed air at 7 psi (approximately 148 kPa) at a temperature of 4 degrees C, how would I calculate the amount needed of that air per unit time to maintain the temperature of a 14 cf refrigerator at 3 degrees C? A 18 cf freezer at -18 degrees C?

So my boss hook me up with the Compressed Air Calculations which we never did previously at our workplace. So started researching about the subject and designed a Compressed air system. The only thing i am not sure about now here is the relation between CFM vs SCFM vs Pressure. Let us take an...

Homework Statement what happens to wavelength if temperature increases? Homework Equations V= lambda * frequency The Attempt at a Solution I'm guessing since no change to frequency is stated?.. and I know that the speed of sound increases as temperature increase. The wavelength would have to...

I want to make a simple air filter(for dust and air pollution) but was a bit confused about some stuff. Basically I've decided to use an exhaust fan to create a vacuum in a sealed box and the air to come in through the filters. Box fans aren't available here, so that can't be used. I want to...

Hi all, I'm having a Kaiser compressor producing compressed air for my garage. I've installed a FRL unit at point of use. I understand that the filter medium adsorbs atmospheric dust, moisture and oil particles in compressed air. Gradually the pressure drop across the filter builds up and I need...

1. Homework Statement As shown above Homework Equations *Not too sure if they are relevant. Pretty sure there's more. We have textbooks from the library as references but we still can't quite figure it out :/ Φ = BcAc = BgAg B = Φ/Ac = (Ni/R)/Ac R = lc/(Ac.μ) The Attempt at a Solution...

The video is pretty alarming: http://www.cbsnews.com/news/china-air-pollution-smog-red-alert-airpocalypse/ This reminds me of the descriptions of London "pea soup" smog from back in the day, except in China it affects a vastly larger area.

I have a basic understanding of how a traditional turbo works. Exhaust gas spins turbine which powers compressor, which compresses intake air. General problem with turbos is lag. Why couldn't you have a separate air intake that fed directly to the turbo (via a filter obviously), for when off...

Homework Statement Two waves of light in air, of wavelength 550 nm, are initially in phase. They then both travel through a layer of plastic as shown in the figure, with L1 = 4.00 μm, n1 = 1.40, L2 = 3.50 μm , and n2 = 1.60. What is their phase difference after they both have emerged from the...

Hi, I have a tank of air which has been depressurized to 0.2bar (absolute) via a vacuum pump, where air can be let in from atmosphere through pipework controlled by a valve. What would be the equation I can use to determine the flow rate into the tank with time? As the flow rate is determined by...

Homework Statement ball dropped in air at 20m/s. why is v=20,v0=0 instead of v0=20,v=0 Homework Equations a=v-v0 / t s=x0+v0xt + at2/2 The Attempt at a Solution a=g=9.8m/s2 I know I can solve it with first finding time(I get that) a=v-v0/t making it into t=v-v0/g so 20/9.8=2.04s but now from...

Hey guys, is it possible to replicate the sounds produced by exhaust gases in a car by using only hot air? Thanks in advance for your responses.

I'm trying to figure out why my back hurts when I sleep and I can't figure out the physics behind it. So I sleep on an air mattress. The mattress fits firmly into the frame, which puts a constraint on the mattress to where it cannot expand on it's sides. Think of the mattress as being in a box...

Hi all, In short: For an air leg or air spring, there is a method using a Taylor approximation to find the spring constant for very small displacements, but I can't seem to figure out how it works. I've learned that air legs don't follow Hooke's law very much at all, except for when the...

Say we have a tire filled with air (equal to ambient air surrounding it in every way). pressure on the gauge is 0. Then, we pressurize it to 1 ATM (15psi). If we heat the tire , the air will be heated and expand based on gas law, or is there a factor that changes it based on the air's...

If a pendulum consisting of a string and a bob is allowed to swing in a vacuum vs in air, which has larger period?

I am a Physics teacher. I made a linear track of length 2m with 400 holes(two rows of 1mm dia). Somewhere I read household vacuum cleaner can be used as a blower. But it does not create sufficient pressure to lift the cart. What should be the specifications of the blower which can be used...

Hi, I am trying to create a device that would "simply" make a bubble under the water. What I am aiming for is production of small bubble but continuously and under the water. When I say continuously, it doeant have to be for extended periods of time, could be just for ~2 hours but the longer...

Homework Statement Methane is mixed with air at a 16:1 per mass ratio at 1atm and 298K. Calculate the mass fraction of argon, nitrogen, oxygen, and methane in the final mixture Homework EquationsThe Attempt at a Solution First, change mass ratio of reactants to mole ratio $$ \frac{16 g...

Hi, I am doing a project for school where I am calculating at what height a balloon would pop from pressure while rising. At the point I am now, I have the initial pressure and the pressure it would pop at. I know work = pressure * change in volume, and that at some point I will need to use the...

Homework Statement I am about to do an experiment where we masure the average speed of a cart released from the top of an inclined plane that has little friction (air track). The speed measurement is done by a photo gate. This is repeated a hundred times. Homework Equations I need to come up...

One thing that has always puzzled me is the fact that in a venturi, air accelerates as it approaches the narrow part of the structure. there are those that argue with the fact that pressure has to raise first , because as we all know, acceleration has to be caused by an increased force (...

Does a circularly polarized laser beam, (say, 1 watt or so at visible wavelengths), impart linear or rotational momentum to air molecules.?? I'm not talking of ionization of air...which I know it doesn't, ...but rather momentum, in particular due to its Left or right CIRCULAR polarization...

A student I am working with showed me a problem they have been working on. In the first part of the question there are two loudspeaker facing each other. The student has been told that they can treat this situation as an closed tube. The frequency of the note is such that its wavelength is...

Hi, If you had a sealed round bottomed flask on some lab scales and you recorded the mass and then you removed all the air with a vacuum pump and then found the mass of the flask again would the difference between the two readings really be an estimate of the mass of the gas in the flask? The...

Hey, I'm working on a project to build a drone which is powered through air jets. The drone needs a valve control system which can control the flow rate (hence the thrust) going to each nozzle in order to adjust it's altitude and stabilty. I need to set up a circuit which can electronically...

Hi. I am new to this forum and would like to get some information on the physics of an air horn. I am trying to design a series of air horns that each play a musical note. The problem I'm running into is what size to make each trumpet in order to produce a specific note. I know that frequency is...

Picture a piping system made up of threaded steel pipes. It is to hold regular water at 7-10 bars. When testing the system for leaks, air is used due to a frost issue and the consequences of a larger leak with water. But what holds water doesn't hold air, and so it slowly leaks out. The question...

What is the best textbook resource (or comprehensive publications, etc) on multi component distillation? particularly the separation of nobel gases from air. Air has all of the nobel gases (except maybe krypton) but they are trace so finding the off takes for these would be incredibly difficult...

Hello I needed to know a logical answer to the question that whether the time of flight of the objects in air increases or decreases as compared to vacuum? Why?

Homework Statement A pipe 30 cm in diameter and 420 m long has a wall thickness of 1 cm. The pipe is commercial steel (ks = 0.045 mm) and carries water from a reservoir to an elevation 100 m below the bottom of the reservoir and discharges into the air. A rotary valve is installed at the...

Is it the typical "get some results and stack the maths together and chuck in some constants to make it fit to get some approximation" or do we understand the rules behind it to derive the formula, such as how the molecules repel each other and how energy is transferred depending on temperature...

1. It makes sense that air drag increases with speed, but is it a direct increase or to the square of the velocity? (so the faster you go the more energy wasted?) 2. What is the relationship between air temperature, pressure, and air drag? I can see how on a warmer day the molecules are further...

If I want to lift a car of 1500 kg with a air compressor and with 50 nozzles, what should be the size of nozzles and what should be the pressure of air compressor and at what pressure will the air come out through nose so that it could be easily be lifted.

Hello, I'd like to know which of these 3 example I sketched would have a steadier and higher air humidity at measuring point, assuming same conditions (except those illustrated as different, like porous media thickness and measuring point), water level and air turbulence within larger container...

How can you calculate air volume in cubic feet per minute through a fan when the only data available is pressure drop and fan diameter? For example, How many cubic feet per minute of air is a fan blowing if it has a diameter of 20" and a pressure drop of -50 pascals?

I saw a video recently describing the lift in terms of pressure. It stated that the Coanda's effect is important. That is the tendency of a fluid jet to flow a curved path. It stated that there is high pressure above the top of an air foil and low pressure below so the air drops or gets...

Hey, I have an air tank that is at a set pressure, say 3000psi, and I have attached a regulator to the end that regulates the pressure down to 800psi. As the valve on the tank is opened the pressure and the mass in the container will decrease. If there was no regulator the mass flow rate would...

Hello, Im asking myself how to calculate the force exerted by air in a inflated unloaded tire. We now that a tire can be modeled as a spring and a damper, with vertical deflection used as spring compression and deflection velocity as damper velocity. But how about a tire with no deflection...

Homework Statement I'm doing a personal project to keep me busy for the winter. I grow Bonsai and I'm making a hospital for sick trees or recently collected ones from the wild that need to recover. I have constructed a 40x40 inch plywood box, 5/8 inch thick walls, air tight. The lid will be...

Hey, So I have a system where there is an air tank (0.2Litres @ 3000psi, 293K) and I have a convergent-divergent nozzle attached directly to it. What I want to know is an expression for how the mass flow rate varies with time as the mass in the tank decreases causing the pressure to decrease...

Is it feasible to turn the abundance of carbon in the atmosphere into graphene, given it is an allotrope of carbon and would it be worth the trouble?