Thickness Definition and 328 Threads

I was thinking of a Fermi-question: the thickness of atmosphere with diffusive equilibrium. And I estimated roughly 10^{5}m (where it should be ~10^{4}m). The difference of order of magnitude to real thickness is 1 (from Wiki). I had a lot of fun, and I am looking for interesting ways other...

When sound hits a wall,part of it gets reflected and part of it gets transmitted due to acoustic impedance difference between solid and air. My problem,and point of this question is that having material or gas impedance number is completely useless unless we know the frequency and wall...

1.A rectangular steelbar of length subjected to tensile force of 80kN. Calculate the change in length if the width and thickness are (40 & 25)mm respectively. (E = 207 GN/m2). Homework Equations E= stress/strain stress = F/A; F =80kN strain = dL/L 3. I just want to know what to use for the...

How does low ambient pressure effect on the thickness of the boundary layer for given flow conditions of gas? In absolute vacuum the thickness of the boundary layer is 0 of course, but it seems that all the boundary layer thickness correlations use the Reynolds number, which doesn’t change much...

A false ceiling made of PVC is fixed around the edges. The ceiling has several point loads distributed on it. Given the ceiling dimensions, yield strength of PVC and the weights and locations of the loads, how do I calculate the required thickness of the ceiling to prevent it deforming...

Homework Statement Homework EquationsThe Attempt at a Solution my initial approach was to just imagine the light rays leaving the focal point and emerging parrallel but then the result had no dependence on thickness how to tackle this problem how does the thickness even factor in

I had an experiment involving FTIR (incoherent light source) to measure the thickness of plastic film through making use of interference fringes. I don't understand how the interference fringes can occur over a frequency range (in term of wave number ν for FTIR) and also how it can occur at the...

Good morning forum, I'm currently in the middle of a project where I'm installing a new chemical storage tank outside. I need to lay a new concrete slab for the tank to lay on. My question is how thick should the concrete slab be? The tank will be stationary, when filled it will weigh...

I am wondering why the material thickness is not factored into calculating bolt shear strength in a joint. I know that it is used when calculating the strength of the material itself and its susceptibility to deformation and tear out but why not the bolt? When you cut a piece of cheese you use...

Homework Statement The internal and external diameter of a hollow cylinder are measured with the help of a vernier calipers. Their values are (3.87 ± 0.01) cm and (4.23 ± 0.01) cm respectively. The thickness of the wall of the cylinder is ?Homework Equations Thickness of cylinder wall= 1/2...

I need to calculate the thickness needed for a retaining wall for a pond. The information I have is as follows: Depth of pond, area of pond, shear strength of retaining material, unconfined compressive strength of retaining material, length of retaining wall (will only be on one side of pond)...

Homework Statement The half-value layer (thickness) of gamma rays in lead is dependent on the energy of the gamma photons before they enter the lead. Find the graph which shows the relationship between the energy of the gamma photons (pasted below) and the half-value layer and read their...

Afternoon everyone, I just found this awesome site where I thought I could enlist the help of a lot smarter people than myself with my project. I want to build a garage elevator to raise and lower various articles from my storage loft. My loft has 9' floor with a 15' ceiling. I was going to...

Homework Statement [/B] Note: inner cylinder thickness = 2.5mm difference between common diameters before shrinking = 4.305x10^-3mm Homework Equations The Attempt at a Solution a) I am not sure where to start without either the inner or outer cylinder diameter but I think I...

Homework Statement A.[/B] Someone is walking outside when the temperature of the air is -10°C. The metabolic rate of walking is 140 Cal/m2hr, and the usual muscle efficiency (20%) applies. They are completely covered by clothing with a coefficient of thermal conductivity of 0.36 Cal-cm/m2hr...

So i have learned about the ability of Faraday Cage for blocking an external electric field. But is the thickness of the conductor effect the ability? Is there any limit of its thickness so that the cage won't be able to block external electric field anymore? I have read and searched about this...

What is the thickness of the Milky Way at the sun's location, and how far is the sun toward the top/bottom?

Homework Statement A thin film of oil (n=1.5) is floating on top of water. When looking directly at this film, a large portion appears red (700nm). What is the thickness of the red part of the layer? Homework EquationsThe Attempt at a Solution Since n for oil > n for air, there will be a phase...

If i have steal bridge that is 35 meter long, 1,2 meter and 15000kg , how do i calculate the thickness so that de bridge doesn't deflect?

Homework Statement As shown in the figure below, beams of light whose wavelength in air is 600 nm are perpendicularly incident upon two transparent thin films (A and B) in the same phase. The thickness of A and B is l. The refractive indices of A and B are, respectively, nA and nB. The...

Hello, I am working on a Project and it has been a while since i did calculations With mechanics. The pool would be made in glassfibre with polyester and will be: L=2000mm W= 1750mm h= 400mm we use the E-module for glass, so we use E= 70 000 N/mm2 I= bh3/12 = 2000mm x 4003 mm /12 = 1,067 x...

Homework Statement How large a surface area in units of square feet will 1 gallon of paint cover if we apply a coat of paint that is 0.1cm thick? Homework Equations Since Volume is L * W * H and we can assume the object is square besides the height which in this case will be the thickness. So...

Homework Statement Givens: - Each of the 2 cylindrical posts are 0.5 inches thick. - The posts and chain links are made of galvanized steel of identical material composition. - The posts and chain links are solid. - Each post is permanently fixed to unbreakable surfaces. The surfaces will move...

Hello! I am designing a vacuum chamber made of a vertical glass cylinder free of contact from any other structure, except by the top and bottom where aluminum disks seal the device. Temperature is the same inside and outside. I found on several books the following formula for the hoop stress...

Just need someone to double check my work. So the bracket is going to be cut out from a steel plate in a weird, rounded out triangular shape, and then a hole will be drilled through it. For simplicity though, let's just say the bracket is a ring with one half of it welded onto a wall. OD of the...

Hello everyone! I previously opened a thread asking about sound wave energy loss in aluminum discs based on thickness. I am looking to find out more about exactly how much using a disc that is twice the thickness of the other, (one is 1/8" and the other is 1/4") sound energy would be lost using...

Is latex balloon maximum strain independent of latex thickness? I have been in search of a latex balloon that is relatively small when deflated and very large when fully inflated. Standard balloons that reach the desired inflated dimensions are much larger deflated than I would like...

Homework Statement The diagram represents a steel tube with wall thickness w which is small in comparison with the diameter of the tube. The tube is under tension, caused by a force T, parallel to the axis of the tube. To reduce the stress in the material of the tube, it is proposed to...

I am trying to figure out the lamination thickness of a transformer to reduce eddy current loss at 10 MHz. I am new to the subject, any help will be appreciated. Also how do I calculate the size of a core to avoid saturation knowing the peak current applied to a 1:1 transformer. Thanks in...

Homework Statement I understand how to find the resonant frequency of a closed pipe but when the thickness of the walls varies, the resonant frequency varies. Is there a formula that i can use to find the resonant frequency of a closed pipe given the length, temperature, speed of sound and...

My name is Joe. I am 49 and have retired in the last year. I was not planning on this, and have had a hard time getting traction around the house. There are projects that I have had in mind and have dreamed about for years and now, I am finally able to get to them. The hobbies I once did that...

Hello everyone, We are trying to fabricate a copper layer that is 41% reflective to a beam of 1521nm wavelength. The formula I have used to calculate the thickness is: R = 1 - e-αt Where R: desired reflectance of mirror t: thickness of mirror that would produce said reflectance α...

what does the relation between the temperature gradient inside the thermal boundary and thermal boundary layer thickness i mean what will be the temperature gradient ( high or low) when the thermal boundary layer is thick relative to the thin one? Kindly explain mathematically and physically as...

How does the current carrying capacity depends on the thickness of insulation of conductor ?

Hi, PF! Recently, while reading chapter 6 of Incropera's Fundamentals of Heat and Mass Transfer I got into a confusion regarding the velocity boundary layer. The book first states that, as the flow becomes more turbulent, the boundary layer gets thicker, as indicated by both figures attached at...

Hi all, I hope you can help... I am by no means smart enough to calculate how thick the material needs to be for a project I am working on, usually I would go by trial end error, but I don't have the budget for that unfortunatley. I'm am trying to work out what steel thickness I would need for...

Hi All, I'm searching for the possible method to determine organic coating thickness cover on steel tole was plated by thin zinc layer. Additionally, I also want to measure thickness zinc plating layer in between these layers (coating on top & steel on bottom) without destructing them. Please...

Let's say we have a plasma of protons or deuterons and electrons; how thick is the 'shell' that the nuclei form in momentum space compared to the 'shell' formed by D2 or H2 in a gas, at room temperature? Will the distribution of momentum be more spread out or more compact, so to speak, in a...

Homework Statement [/B] For your cabin in the wilderness, you decide to build a primitive refrigerator out of Styrofoam, planning to keep the interior cool with a block of ice that has an initial mass of 24.0 kg. The box has dimensions of 0.5 m x 0.8 m x 0.5 m. Water from melting ice collects...

I'm Having a part machined with a cylinder shape approximately 14 inches in length with a cylinder hole in the center with a diameter of .930 . I have no idea how thick the cylinder wall needs to be. I have looked up and used hoop stress calculators online but I do not understand if they take...

... sound wave? I need a simple method to calculate the impedance between water and silicone as ultrasound passes through them i.e. how much of the signal is reflected at the water silicone boundary. The problem is I am having trouble finding the required equations, Wiki is extremely...

Hello everyone! I wanted to ask if the wing thickness is the same meaning as camber? Thanks in advance

Homework Statement Homework Equations Young's Modulus, E=σ/ξ Stress,σ =F/A Strain, ξ=x/L The Attempt at a Solution As diameter and tension are constant, so stress must be constant I assume.. So for the same Young's modulus, if stress is halved, then strain must be halved too I guess. But I...

< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown >[/color] What do you understand by the term "Critical thickness of Insulation"? What is the critical thickness of a plane wall? Derive an expression for the critical thickness of insulation...

Hello, I am simulating an experiment I did in the lab where we had air flow over a tray of water to determine the mass transfer coefficient scaling with velocity, as well as boundary layer thickness scaling with velocity. Now I am using COMSOL to simulate the experiment, and here is the...

I understand that convex lenses cause light rays to converge while concave lenses cause light rays to diverge. But what is the relationship between the thickness of these lenses and the extent of the convergence/divergence of the light rays?

Homework Statement If I'm looking for standard sizes of nozzle thickness. Homework EquationsThe Attempt at a Solution Should I be searching for the standard thickness of plates that are used to form the nozzle?

Hello, I'm doing an experiment where I will be blowing warm air parallel to a stagnant water surface, and I will investigate the scaling of air velocity with mass transfer coefficient. I am trying to find some kind of scaling of the concentration boundary layer thickness with air velocity, and...

hello guys, so i want to ask whether the thickness of a convex/concave mirror affect its focal length and the sharpness of image formed? and what really determines the sharpness of image? thanks for replying in advance! :biggrin::biggrin:

Homework Statement A sheet of mica ( approximate 6-7 µm) covers one slit of a double-slit apparatus and has a n= 1.582. There is a central maximum of 539 nm. What is the exact thickness of the sheet of mica? Homework EquationsThe Attempt at a Solution I think you can solve this with the...