Air Definition and 1000 Threads

Homework Statement To research the physics of how a hot air balloon works. Homework EquationsThe Attempt at a Solution I just would like someone to check the main points I am going to include. The air inside the balloon is less dense because it is heated so that particles of air are further...

I am trying to calculate the flux density of an air gap in an electromagnet. I am following this page that calculates the flux density in a C core with an air gap. My confusion is that I am using 50Hz AC instead of DC I have control over the voltage amplitude since I would be using a variac to...

All the physics classes I've ever had modled object motion as though it where in a vaccuum, becuase air resistance is obviously a pain in the but to account for. Mathmatically how would i account for it? Say after one second of free fall how much of my velocity would be lost due to air? Im...

I have noticed that after wearing a respirator (dual-cartridge activated charcoal by 3M) for an hour or so, when I remove it, the ambient air smells slightly sweet, almost like slight hint of ozone. After a little while without it, the smell seems to "go back to neutral" or nothing unique. I...

I am trying to make a CO2 air gun and was wondering if jb weld can hold the pressure from the 12g CO2 cartridge in this set up with a CO2 bike pump connected to a valve that can wothstand the pressure

Homework Statement A closed cylinder of 0.25 m diameter is fitted with a light friction-less piston.The piston is retained in position by a catch in the cylinder wall and the volume on one side of the piston contains air at a pressure of 750 kN/m2. The volume on the other side of the piston is...

if i sucked air out of an oil well after drilling a few feet and closed the hole by any means and continued drilling without allowing air in, will that eliminate change in influx and won't result in a kick? or because i can't suck air completely out so the delta p will be really high?

hello everyone, i hope you're doing well, i am new to this forum so i am not sure if this is the right place for my question what i am doing is trying to calculate the air flow needed for intake of an RC engine Zenoah G320RC in the attachment files, it's a pdf for the info about the Standard...

Hello, I am currently working on a project which involves compressing air at high pressures and temperatures. I spent hours having a look for a pressure and temperature dependent equation for the dynamic viscosity of air but the only ones I could find were all temperature dependent only, such...

The index of refraction for a gas depends on temperature, as well as pressure. What is an experiment that would determine the temperature dependence of the index of refraction of air?

Homework Statement An RAAF Roulette aeroplane is performing a low fly over at an air show. Under the current wind conditions its top speed is 450 km/hour, and it will fly directly over the crowd at an altitude of only h=340metres approaching from the North. When the aeroplane is only...

Homework Statement Consider a given monochromatic component of sunlight. The electric field drives a given air molecule. Each oscillating charge of the air molecule radiates waves in all directions, some of which travel to the eye of a given observer. But, for a given molecule (call it No.1)...

This question is regarding the general fluid dynamics involving warm air advection aloft a persistent cold air pool in a small basin that is recessed in a horizontal planar surface. For scale, the basin has a compound parabolic shape, with a 30° viewing angle, a .146m radius at the base, a .292m...

Why do compressors for example in the fridge make that vibrating sound, I've heard a similar vibrating noise in fans which are compressing air as well... i think. Why does compressing air make sound? Can air hitting air create sound waves?

So in my physics class this last semester, we learned about normal force, weight and centripetal acceleration and all that good stuff. So i got to thinking about a ball on a string being spun around my head and i got to thinking about the force diagram you would draw for that, and obviously you...

Hi, I recently did an experiment whereby we investigated the velocity distribution of air expelled from a round nozzle whose diameter, D, was 30mm. We have been asked to calculate the volume flow rate at distances of 2D, 6D and 10D along the centreline. We found the flow rates to INCREASE...

Perhaps someone here can help me. I have looked at many day cares and preschools here in Sunnyvale, California and the air quality is poor. Many house 12 to 20 kids (whose respiration is effectively similar to adults) and 2 teachers in a room that is small enough that if it were a workplace...

Homework Statement There isn't really a "problem statement", but more so a conceptual prompt. Say you throw a ball in the air with some velocity V. The work done due to gravity and drag is Mgh + Fdragd. What I don't know how to do (and there is no additional information, the prompt is very...

Hello, Right now I'm doing a Final Year Project 1 which is Air Hockey. The different between our air hockey and normal air hockey are our air hockey is octagonal shape. but now I'm stuck at calculating the air pressure for the table. can you help us? again this is just a school project not...

Hello, I have searched and searched but cannot seem to find an apparatus to solve my problem. For this project (see attachment for the drawing) I need to be able to drop a steel ball into a tube in position A and have to go into the side of the water tank and fall to the bottom of the tank...

Hey, I'm a physics student looking a new laptop. The main uses for the laptop is coding (python, matlab), maybe basic simulations, ocassional gaming (starcraft and hEarth'stone), watch movies and do essays. The simulation part is just basic things, for more complex stuff i have access to a...

Homework Statement 1 kg of moist air and 1 g condenses. What will the change in the temperature of the moist air be? Heat of Vaporization = 2.5*10^6 J/kg 2. The attempt at a solution The moist air will warm due to condensation. Heat of Vaporization=2.5*10^3 J/g Specific heat at...

Evening all, I've recently undertaken a project where my roll is to analyse the suspension of a mountain bike. The suspension unit in question is a Rock Shox Monarch RT3. To give a brief summary: The shock uses compressed air as the spring, the pressure is adjustable via an air valve. The shock...

Hello everyone, I am working on a project for work, and I have a small problem I'm sure someone could find a solution to. I have a tank of isopropyl alcohol that I am pumping air into. The air bubbles up to the top of the tank and creates lots of agitation in the alcohol, which splashes around...

Hello all, I wanted to say thanks to everyone on this forum who dedicate their personal time to enlighten so many like myself. I am a fan of physics and consider myself a student for life. I recently bought an Indoor Air Quality (IAQ) sensor/monitor to test my air purifier and as expected...

I am trying to develop a Ventury https://www.physicsforums.com/javascript: Pump using Compressed Air a d Motive Fluid and Suction Fluid is Water from Shallow Well. Compressed Air parameter is 6CFM Air at 7 bar using 2hp Motor & Compressor set, and required Suction Lift is about 5m. Discharge...

This is a really tough problem. I have spent years studying and experimenting about this. Outdoor air contains tracers such as dust, pollen, etc. called aerosols. It is possible to use LIDAR to detect these at distances in the scale of kilometers away. But lasers of the power to use at even 1km...

How do I determine the pressure drop of air across an opening? For example if I have 3,000 L/s (3 m3/s) and an opening of 8.4 m2 I know the velocity is 0.4 m/s. If the free area is 80%, the velocity increases to 0.45 m/s. What I'd like to cal is the pressure drop in each case. Cheers

Homework Statement Consider air expansion inside a cylinder. Assume that the volume and initial pressure is 1 ft^3 and 1500 PSI ABS respectively. If the expansion process is reversible and the path is given by P.V^1.4=constant. Calculate the total work done by the gas to reach the final volume...

You have a cylindrical chamber with a 5cm ID and 55cc capacity filled to 4,000psi of air at 70*F and want to released the air threw a tube of .5cm ID. What's the initial velocity (in fps please) as the air leaves the chamber's end directly threw the .5cm tube? What's the initial velocity as the...

this should be easy. suppose i have a very large spaceship holding a tremendous volume of air at 14.7psi with a density of .0023769 slug/ft^3. i put a hole in the side of my spaceship that is 6" in diameter which vents to the vacuum of outer space. what is the velocity of the escaping air? i did...

I need a way to generate cool air outside when temperatures are 90s and above. Basically what I am thinking of doing is essentially like positioning a fan right beside a bowl of ice cubes. Only in my case, instead of using ice cubes, an electrically powered cooling device that can slightly...

the vw type 1 engine comes with flaps that close when the engine is cold. i know the flow through the fan doesn't completely stop but for the sake off argument let's assume that is does. the fan is spinning but there is no flow. what power is required to maintain the pressure differential...

Hello there I'm having real difficulty with a problem to do with air cylinders and would really appreciate some help. I'm attempting to replicate the human breathing system in a simplistic form but I'm having trouble calculating the force required to provide the correct airflow rate at the...

hello, I have a small project to made and one of the problems is humidifying the inlet air for a fuel cell with open cathod. I can't use Perma-pure technology or similar things, because there are no tubes in which the air flows; it goes directly inside one of the faces of the fuell cell and...

Homework Statement Measure the density if air at normal atmospheric pressure. You can use the following equipment: One scale with an accuracy of 0.01g Two empty glas bottles (≈0,33 liter each) One big bowl with water One cork with a valve and a vacuumpump Homework Equations Not knowing how...

Hello everyone, I am designing a machine that will utilize jets of compressed air underwater. Does anyone have information about the physics of gas underwater? I would like to know how far the jet will travel before floating upwards, based on the pressure of the air and diameter of the nozzle. I...

Homework Statement To plot a TS diagram given the relevant data here http://imgur.com/Q9RNL8P for an air conditioning unit. Homework Equations R134a is being used in an air conditioning unit, steam tables for -5hf 0hf and -5sf 0sf written below in exrapolation. The Attempt at a Solution I've...

Hello, I want to design a mechanism for tilting an air hose (not more than 10 kg) to a desired angle (anywhere between 0 and 90 degrees depending on operating conditions) and holding it there. I've tried googling this up but just can;t find what I was lookin for. Then I searched for...

I may be in the dark here but many of the media-dependent constants like permeability, permittivity and even the speed of light are ALMOST identical in both media ie. vacuum and the atmosphere of the Earth. This exists even though the 2 are very different because one is almost empty and the...

am trying to simulate air conditioner in open modelica and matlab.. is there any library like hvac so that i can do the simulation in mush easier way...

My questions is about the conversion of a range of wavelengths in Hz, such as for an optical filter, in a medium different from air. Since the refractive index n is higher than 1, (let's say n=1.5) and than the value of c is almost 2x108 m/s, also the equation in the link below has to be...

what will happen when a grenade blow up in a room without air in it?

Is there an air compressor that can run on 12v continously delivering 150psi?

and after sucking air out we seal off the hole in order to eliminate any change in influx and pressure downhole? and if possible, what would be the procedure?

Homework Statement A 15 cm. radius cylindrical air duct is used to replenish the air of a room 10 m.*6 m.* 3m. Every 10 minutes. Determine the speed of the air through the duct in m/s. A1=15 V1=? A2=19 V2=0 Homework Equations A1V1=A2V2 The Attempt at a Solution 3.14*15^2 * ?= 19*0=...

Hello Everyone, I am working on a project with a friend and neither of us have any formal training in engineering but we generally are quick learners. We are both familiar with many of the gas laws and are trying to calculate the equalization pressure between 2 cylinders/vessels or tanks used in...

Hello everybody, this is my first post on here. I'd like to make my entrance by asking a question that's very important to me. I would like to ask what it's like to get your University PhD in Physics paid for by the Canadian Air Forces. I've been asking a lot of people, but I thought its time to...

Even though light is a transverse wave it travels through air . Why?

Homework Statement A 50-kg parachutist descends at a steady 40 km/h. What force does air exert on the parachute? Homework EquationsThe Attempt at a Solution Okay, I know that F_net = ma, where F_net is the net sum of all the forces acting on the parachutist. The two forces acting on him are...