Air Definition and 1000 Threads

  1. G

    How to Factor Air Resistance into Basketball Trajectory Calculations?

    Hi all, I will be doing an experiment in which I will be rolling a basketball down an elevated ramp. After leaving the ramp, the basketball will free fall for 1.25m before reaching the ground. I was looking to come up with a theoretical trajectory for the motion of the ball, the issue is that I...
  2. System1459

    Air Pressure between two air tanks

    So I am a heavy vehicle mechanic. One of my vehicles has an air starter with a separate air tank dedicated to the starter. This tank is fed from the main air tanks on the truck with a check valve to only allow air into the starter tank. The gauge on the dash only displays the pressure in the...
  3. B

    Air volume in the tank, volume vs pressure

    New to forum Most air tanks are categorized on volume of air they hold . The question I have is this that a 5 gal air tank that holds 160 psi , is it equivalent to a tank that holds 2.5 gal of air at 320 PSI ? if not then is there a formula to figure this ratio . Thanks
  4. Hepth

    Dynamics of pumping fluid into a cylinder with an air hole?

    I should be able to do this, but its been a while and maybe I'm making this more difficult that it should be. Assume you have a cylinder nearly sealed but with an outlet hole at the top. I want to pump a fluid into the canister, pushing the air out of the hole, and time how long it takes. The...
  5. SalusVF

    Air velocity inside a pipe (natural convection)

    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...
  6. A

    Projectile Motion problem involving air resistance

    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...
  7. M

    Finding the effect of air resistance on period of oscilation

    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...
  8. S

    Mean distance between air molecules

    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...
  9. A

    What is the velocity of a falling object with air resistance?

    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...
  10. Ian Baughman

    How Does Temperature Affect the Lifting Capacity of a Hot Air Balloon?

    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...
  11. I

    Air conditioning unit with slightly open window

    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...
  12. P

    Air Check Valve: Preventing Air Pressure Backup in Lift Fans

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

    Using Isothermally Compressed Air to Cool a Refrigerator

    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?
  14. Shariq Qazi

    Air Compressor Pressure vs CFM vs SCFM

    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...
  15. T

    What happens to wavelength as temperature of air increases?

    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...
  16. R

    I Simple suction air filter: items and preventing implosion

    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...
  17. D

    Equations explaining pressure drop across an air filter

    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...
  18. E

    Determine flux in air gap (Magnetic Core)

    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...
  19. zoobyshoe

    News China's Alarming Air Pollution: 'Airpocalypse' Smog

    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.
  20. D

    Automotive Powering a turbo with intake air

    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...
  21. A

    Two waves of light in air travel through a layer

    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...
  22. JCB123

    I Air flow from atmosphere into a tank

    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...
  23. MrGoATi

    Ball dropped in air at 20m/s, why v=20 not v0=20

    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...
  24. K

    Automotive Can hot air replicate the sound effects of exhaust gases?

    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.
  25. Z

    Pressure distribution on an air mattress

    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...
  26. S

    Approximating a spring constant for an air leg

    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...
  27. Z

    Gas Law applying to air vs water vapor

    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...
  28. L

    Pendulum in vacuum vs with air resistance

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

    I What Blower Specifications Are Needed for an Effective Linear Air Track?

    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...
  30. Tomimo

    Making bubbles and trying to use Trompe

    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...
  31. I

    Methane mixed with air at 16:1 by mass

    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...
  32. C

    Finding Pressure change as height changes with Pfinal given

    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...
  33. P

    Air track - Inclined Plane experiment

    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...
  34. Z

    Bernoulli vs Newton - air flow characteristics

    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 (...
  35. P

    I Can a circularly Polarized Laser impart momentum to air?

    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...
  36. resurgance2001

    B Resonance of air between two loudspeakers

    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...
  37. G

    B Density of air experiment, why it yields these answers?

    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...
  38. I

    Air flow: pressure increase over a constriction and fan

    Homework Statement So a fan sucks air through a pipe, and the outlet is near the fan, and thus the inlet where the air starts to travel is furthest away. If the diameter is constant the speed would be constant due to the continuity equation, and I assume we neglect compression effects in...
  39. A

    What is the Best Control System for Compressed Air in a Drone?

    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...
  40. Grant M

    B Air Horn Physics: Calculating Size, Length & More for Musical Chords

    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...
  41. T

    Testing water pipes with air pressure

    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...
  42. R

    Distilling Air for Nobel Gases: A Comprehensive Textbook Resource

    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...
  43. A

    Time of flight objects in air versus in vacuum

    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?
  44. CivilSigma

    Determining Pipe Pressure of a system that discharges to air

    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...
  45. victorhugo

    What do we know about the formula for air drag force?

    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...
  46. victorhugo

    Air friction and speed & 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...
  47. Vikramaditya

    Lifting a car of 1500 Kg through air compressor

    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.
  48. Alfreds9

    Water wicking up porous media and air humidity ?

    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...
  49. R

    How to calculate air volume of a fan using pressure?

    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?
  50. T

    Plane's Coanda's effect and jet engines sucking in air

    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...
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