My question is harder to explain than I would imagine it will be to answer. I'm trying to vaporize a non-combustible fuel source with an internal radiant coil surrounding a small vaporization chamber consisting of a heat-resistant cotton-like material being fueled by a constant drip fuel pump...
Hey guys, long time reader first time poster.
I'm undertaking a project in partial fulfillment of my Mechanical Engineering degree with regards to the cooling of an intercooler heat exchanger with an exterior water spray. basically i have an intercooler and i am using a hair dryer to supply a...
Homework Statement
Air is drawn into a compressor at normal temperature and pressure (N.T.P.) and compressed to a pressure of 6 bar gauge. After compression the air is delivered at 1.2m3 min–1 and cooled to a temperature of 30°C, at which point condensate is collected at the rate of 2 litres...
Good afternoon.
I need to know if the thermal power of the air extracted from a building is greater than 80kW.
I know the flows entering and leaving the building. Also, I know the temperature of the air inside and outside the building.
How do I calculate the power of the air extracted?
thank you
Homework Statement
A student stands 86m from the foot of a cliff, claps her hands, and hears the echo 0.50s later. Calculate speed of sound in air.
Known
•86m
•0.50s
Homework Equations
V=331.4+0.606T
The Attempt at a Solution
V=d/t
V=86m/0.50s
V=172m/s
Is that the first step to the problem...
The title is explanatory. I know that an iron core yields a stronger electromagnet. What if you have an electromagnet with an extremely tiny air coil relative to its volume? Does the small air coil diameter effect the electromagnet?
Hi,
First-timer here! I'm designing a physics project that involves pumping a certain pressure of air into an empty bottle.
SETUP: The bottom of the bottle has a small hole through which a thumb tack fits tightly; the top (cap-side) has a valve through which the air is inserted. The bottle is...
Given the following situation:
Given that A is air tight how would one go about working out the air pressure required to achieve:
Any assistance would be appreciated.
A typical example is a iron chair gets cold in winters and wooden chain not. We all know iron is more conductive but how this thing possible at molecular level of conduction of heat from metal to air. In general conduction I know it is possible due to vibration transfer of molecules but how it's...
Homework Statement
"Infrared light doesn't travel through air easily". Why is that? Is it because there are lots of molecules that absorb the energy so that a reaction occurs?
Homework EquationsThe Attempt at a Solution
Homework Statement
The resonant length of a closed air column at the first resonance is 0.375m, what is the wavelength when at 4th reasonance
Homework EquationsThe Attempt at a Solution
1/4λ=0.375m
λ=1.5m
1.5m/7 = 0.214m
hi guys... am working on a variable refrigerant flow (VRF) type air conditioner.
my aim is to change the capacity of the compressor based on load change. i can vary compressor capacity by using inverter...now my doubt is on what basis i should change compressor speed for muti evaporator...
Hello--can anyone please help me estimate the PSI required in an air mattress to minimize or even prevent displacement if a person, say 220 lbs, walked across it?
Mattress material and wall thickness variable. Surface area variable.
Also, if scenarios where the person is standing still...
Am experimenting with an Omega Engineering AHP 7561 standard air heater rated for up to 240v. Specs include ability to keep a 20 cfm flow exiting @1000F while pulling about 10A @220v.
Nichrome melts around 2400F. I'd like to produce small bursts (lasting a few seconds) of very hot air, like...
1. assume air is an iseal gas at 25C and 100kPa. the mole fractions of components are nitrogen_0.7567
oxygen=0.2035 water vapor=0.0303 carbon dioxide=0.0003 Calc. min work to seperate
a-1kmol O2 at 25C 100kPa
b-1kmol N2 at 25C 100kPa from atmosphere
Homework Equations...
Picture a Ø160mm duct 10m in length, open at each end. Then I install an in-line fan at one end so that it blows into the duct and just let it run at full power. How can I determine what the air flow will be? I startet thinking about it and was just surprised that I didn't know how to approach...
Really quick question, what exactly does the fan of the outside part of my split ac do? That fan seems to just make wind for no clear reason. I'm curious to know what it actually does.
Hi all,
Is there a correlation between an Air Dryer capacity and the exhaust pipe diameter? How would a small exhaust pipe diameter (not able to exhaust air enough) affects the capacity of an air dryer? If it does, could you expand on this? Thank you
Hi! I'm a teacher in Mechanical Engineering, and I organize a (yearly) student's project where they design and create a cooling machine. The machine works by compressing air, cooling the compressed air, and then rapidly expanding it. This can lead to temperatures of minus 7 degrees Celsius.
I...
Homework Statement
vertical glass tube with height of 2H. H is 760mm.
the lower half is full of an unknown gas. the upper half is full of mercury.
The gas gets heated so it pushes the mercury out of the glass tube.
What temperature must the gas be heated to?
here is the photo if, for some...
this question relates to creating free superoxide so it is not a superoxide of anything. another more un-accurate but common name for it is a negative air ion.
in air, ozone is always going to be co-created in any process that creates superoxide.
a HV electrode (-) in air produces mostly ozone...
Homework Statement
Compute the average number of molecular hits, per unit time, experienced by a square inch of surface exposed to air, under normal conditions. Assume air is a mixture composed of 80% N2, 20% O2, both of which are assumed to be ideal gases. You will have to perform angular...
Homework Statement
For a rigid, impervious, closed tank - The volume of tank is filled with 70% water and the rest is with air- The initial temperature of the tank is 20 °C, and the absolute pressure is 1 bar. - What would be the final pressure if we raise the temperature to 200 °C?
Homework...
Homework Statement
Some hot air balloonists find themselves accelerating downward with acceleration a at a moment when the mass of the balloon plus the passengers and cargo is M. They want to accelerate upwards at the same rate, so they toss out some of the cargo mass m (and maybe one or...
in induction motor there is air gap between stator and rotor. the air gap needs to be as small as possible. but some air gap is needed for mechancial reasons.
i understand that a big air gap would reduce power factor as you'd need more magnetizing current. but are there any advantages of big...
Sir, Kindly let me know how to calculate flow rate (cfm or Litre/m) of air flowing through a pipe of 12 mm dia from a reservoir at pressure 7 kg/cm2 to atmosphere.
i.e ;- how much volume of compressed air could pass within a minute through a "X"mm dia pipe from a constant pressure (7 kg/cm2)...
Homework Statement
a magnetic circuit with a coil of 500 turns and a core of sheet steel has an air gap of 1mm. the sheet steel has a mean path length Lss = 0.25 m and a cross section that measures 1cm x 1.6 cm. (assume: u air = u0(not) = 4pi x 10^-7 wb/(Am).
determine how much coil current is...
Homework Statement
Hello, I'm having troubles figuring out what seems to be a pretty simple physics question.
Attached is an image of the problem. what I am trying to solve is how a funnel effects the speed of air. The input velocity (v1) is 30 km/h, and I am trying to find the output velocity...
Hello all. I am new to the forums and this is my first post.
So, I am currently a junior double majoring in Mechanical Engineering and Physics. My college has a 5 year program meaning I have another 2 years after the upcoming spring semester. I have grown an interest in joining the Air Force...
Hey all, is there a formula that can calculate the energy losy by a photon traveling through air at 1 atm per meter given frequency? Any help apreciated.
I am working on a project which involves air nozzles. I am interested in estimating the time it takes for air particles after they leave the nozzle to reach a particular distance away.
I have the following information--- a converging nozzle, the speed with which it is coming out of the nozzle(I...
Hi, new here, with bits & pieces of basic college physics rattling around in my brain from years ago, so explain things at that level, please.
I am building a cold frame in order to try growing food through the winter in NJ, USA. It will get below freezing here at night but not every day. I...
Guys I have a doubt or rather a misconception
It is as follows:
Consider a container with a partition having a gas A occupying 2/3rd of the volume and gas B occupying 1/3 rd of the volume
Now suppose we remove the partition .As a result,gas A will occupy the whole volume of the container and gas...
If you try to mix water and sand, the sand will mix around and eventually fall to the bottom. Sand and water can't make a solution, so they separate. However salt and water can make a solution, and they don't separate. If air is a mixture, why don't the gases separate?
1) So, pretty much what...
Homework Statement
A ball is thrown vertically upward with an initial speed of v0. It experiences a force of air resistance. The positive direction for all vector quantities is upward.
Does the magnitude of the acceleration of the ball increase, decrease, or remain the same as the ball moves...
A ball is thrown upwards from a building of height 2x with an initial velocity of v1. The velocity when it hits the ground is -v2. What is the height of the ball when it is at maximum speed?
Since it is at its max speed when it hits the ground, would the answer just be 0x?
I am currently doing a research on energy consumption of Room Air conditioners based on BEE rating. Are there any available industry benchmarks for energy consumption of Air conditioners by rating of the AC?
For instance, for the given scenario (defined constants) below, any inputs on how to...
I want to design a wind toubine ,I know the wnd vel,I need certain amount of power ..How to design it and how to calculate at which rpm will it rotate to deliver my required power?
1. A ball falls to the ground through the air. Is the energy of the air conserved?2. None3. When a ball falls to the ground a transformation of energy occurs. The previously stored potential energy gradually becomes kinetic energy during its fall. The energy conserved in the air is the slight...
so last night I get on a sleep number bed and the remote reads 35 (unitless - I am assuming this number is related to pressure.) I click it down once to 30 and it deflates nearly completely. I get off the mattress, the reading drops to 5 or 10 and the mattress begins to inflate to 30.
So this...
Known: Heater intake is 1/8", output is 1/4", pressure drop is ~8.3 psig at 5 CFM flow. Minimum SCFM is 1. The blower would need to put out a minimum of 1 SCFM and be variable above that to a max of 5.3 CFM
How do I determine what size blower I would need to overcome this pressure and obtain...
Homework Statement
Homework Equations
P=hρg
The Attempt at a Solution
The length of mercury column ...
(1) on the left side (exposed to atmosphere) would be ( 760 + x/2 )mm
(2) on the right side (exposed to atmosphere) would be ( 760 + (50-y)/2 )mm
(3) on the left (exposed to air at...
Hello all!
I am designing a machine which consists of a horizontally mounted vessel which has a movable lid. The lid is moved up-down with the help of a pneumatic cylinder & is guided on linear bearings.
My question is during maintenance, when the lid is UP, and for any reason there is a...
Homework Statement
Homework Equations
F=ma
The Attempt at a Solution
As the diver's velocity increases, then force F due to air resistance would increase, so D is out. And C is out too, as air resistance would be equal to its weight at terminal velocity. The answer is B, but how do we know...
Consider a small enclosed vertical shaft (say 50x50 cm) inside an aparment building with an Ø160 mm uninsulated steel exhaust duct moving air at anything from +20°C to -10°C depending on time of year. Surrounding areas are at room temperature, 21°C.
The air surrounding the duct inside the shaft...
This question might be out of the scope of this forum but,
Assume an object (lets say cube) rests on an even floor that at all points is vibrating vertically at the same frequency at all times. (a platform going up and down)
The floor is vibrating vertically at a FIXED displacement.
How can i...
Homework Statement
I collected data for an experiment involving air resistance. We made paper disks and timed how long they took to fall over a fixed distance. We changed the radius of the disk. We found that as you increase the radius they take longer to fall. I am trying to explain my results...