Diameter Definition and 508 Threads

Hello, I have question about vent for tube that is 5" in diameter and 160ft long. Could 5" vent push/extract air to/from tube above? If possible, how much CFM should vent have? Thx 😊

I measured the maximum diameters of 15 regular polygons with side lengths of one. Is there a way to calculate the maximum diameter for regular polygons of any number of sides without using pi or any nonterminating numbers? 03-Sided = 1 04-Sided = 1.4142 05-Sided = 1.6180 06-Sided = 2 07-Sided =...

Cosmologists say that the observable universe has a diameter of 93 billion light years. Does this mean the universe has a center?

I am a writer completing a science fiction novel involving a four foot diameter black hole (with approx 1.5 times the mass of Saturn) At one point in the story, this small black hole has sling shot past the sun, is headed outward toward the Kuiper belt & Oort Cloud. As it moves, the sun's...

The pump has an outlet size of 4 inch 1) In case 1, 4 inch pipe is connected at length of 20 m 2) In case 2, 2 inch pipe is connected using reducer In both cases the pump outlet conditions are same( having same flow rate at a given pressure) What happens to pressure at the end of the pipe in...

Homework Statement: I am a writer completing a science fiction novel involving a four foot diameter black hole (with approx 1.5 times the mass of Saturn) In my novel, the black hole is being drawn toward our much more massive sun. I assume the black hole would begin to consume plasma/energy...

I really do not understand what they are asking here...wording here in english is a bit confusing to me...but from similar examples, i made use of the approach below (which i still do not understand) hence my post. ##\dfrac{30π}{60 ×180} = \dfrac{0.0254}{d}## ##d = \dfrac{274.32}{30π}## ##d=...

Hello, I'm trying to help my kiddo with some math, and unfortunately this is stumping me. A full reel of cable has a diameter of 60 inches. A job requires 314 feet of cable. How many turns of cable should be taken off the the reel? The answer is 20 turns, but I can't seem to figure out how...

https://phys.org/news/2023-03-massive-giant-exoplanet-tess.html It is one of the most massive and densest exoplanets. For comparison, Mo has a density of 10.22 g/cm3 and Ta has a density of 16.6 g/cm3. I would suspect that some of the density is derived from the high compressive pressure of...

Hello, I am trying to calculate the turbine RPM for a turbine in a closed pipe. I know the air velocity and pipe diameter. Can this be done?

Greetings, I've come across lots of exercises regarding Bernoulli's equation. However, never seen one where the top of the vessel is closed, and fluid flow exists via gas (air) going in. Has this problem been studied in the past? Assume a cylindrical vessel filled to the maximum with a D-sized...

Alright, this is more of a conceptual question than a HW question that will nonetheless help me design something. In the attached image, air is flowing through a large area tube and then a small area tube from right to left. A collaborator previously figured out the equation for measuring the...

I think the answer is that the elastic potential energy will be a 1/16th of the original value. This is my reasoning: 1) If the diameter doubles, the cross sectional area is 4 times the original value. (from A= πr2). 2) F= stress/area. Force (load is the same). If cross sectional area...

I have a friend who wants to replace his scope. Has a balcony overlooking the lake, so less about stars; more about Moon and terrestrial. So he's interested in a (right side up) refractor. He can save on the mount by getting an alt-az instead of an eq. He's looking at this 4" Celestron...

Probably, to satisfy the significant digits rule for division, we should consider ##r = 5.0 \div 2.0##. But I'm unable to come up with a reason why significant digits rule should not apply to ##r= d \div 2##. Also, if we apply significant digits rule to this calculation then we loose accuracy...

Ball drops cm P (Momentum) Metal 10cm 92.4 Marble 10cm 29.4 Ball drops cm KE Metal KE 10cm 64.68 Marble KE 10cm 20.58

What diameter does a photon have? Does it vary and if so within what range?

Hi all, I'm a tinkerer with no formal engineering background, but enjoy read about physics and engineering in general. I'm reading up on fluid flow and I'm a bit grasping at the concepts. As far as I understand it, flow rate, pressure drop and pipe size are all interrelated, where one affects...

Imagine a bolted joint with a washer between the bolt and the surface. Assuming the washer is always covered by the bolt head so it's getting a consistent load, does the washer's diameter impact the static friction being imparted on the surface? I see two conflicting ways of viewing this...

I have a empty bottle and immersed it into the water, where the pressure inside the bottle is equal to air pressure. If I want to make a hole on the bottle, how big is the hole to prevent the water leak into the bottle at different depth? what kind of parameter is involve in this phenomena? can...

I would like to know how to calculate, for any specified frequency in Hz, the required diameter of a 90 degree phased, quadrature coil array such that its generated EM field achieves rotation at the speed of light. Could someone please provide an example of the calculation using a specific...

Hi All I'm sure this question has been covered previously , but when searching I do not find a definitive answers. I recently watch some talks given by Kip Thorne that had me thinking about black holes and their densities. So my deduction is as follows . Using General relativity, and...

I need to prove the above statement. I have a very strong gut feeling that the above equation is not true, and so I need to find a case where the graph diameter is greater than the average pairwise distance. First off, I would like to clarify about the average pairwise distance, which is given...

What is the method of calculating the diameter of a solar system knowing each of its planets distance to the star? Is it a matter of doubling the distance of the furthest planet? What about when a solar system has more than one star?

So I know current is just coulombs/second. Electrons are also in the unit of coulombs, so I can get coulombs to cancel. 7.9C/s/1.602E-29C = 4.93133E29 1/s Now I just need to get mol on top. There are 6.022E23 electron in a mol so 4.93133E29 1/s / 6.022E23 atoms/mol = 8.1889E5 mol/s. Now my...

Hi, Can anyone let me know if I had done this Q correctly? Thanks for any help!

I am writing an article about the Hubble Tension and when I was looking through the angular diameter distance I get confused over something. In many articles the angular diamater distance to the LSS defined as the $$D_A^* = \frac{r_s^*}{\theta_s^*}$$ where ##r_s^*## is the comoving sound...

Hello, I am trying to change a 0.9mm screw with a 1.0mm screw. The material is 18k gold, and so the hole is to be threaded. Is it ill advised to force the larger screw in without tapping the smaller hole? the difference in screw size is just .1mm, and we assume the thread pitches are...

Least count of the screw gauge = Pitch÷No. of divisions on circular scale=1.5÷100 mm =0.015mm According to me,in this case the main scale reading should be taken as 2 mm because it is the one which is visible and circular scale reading should be 76. So, Diameter=2 mm + 0.015×76 mm = 2 mm + 1.14...

I am confused because the question implies that I need to do some sort of calculation with Kepler's law. I got ##r+d = \sqrt[3]{\frac{T^2 GM}{4 \pi^2} } ## But don't understand why I need this, since I already have the distance and the angular diameter should be ##\arctan (2R/d)## I think I...

Is there a limit on the minimum diameter that a collimated electromagnetic beam must have (lasers or masers), in terms of its wavelength, or it is possible to create a beam with its diameter smaller than its wavelength? I'm considering a colimated planar wave directly from the source, and not...

Hello all this is my first post. I am not an engineer, but I wish I was. I have been enjoying watching Dan Gelbart!s YouTube Chanel. His air bearing has me wondering about the relationship and apparent conflict inside ball bearings. How does the ball travel around the shorter distance...

Five identical semicircles are arranged as shown. Find the diameter of one circle. \draw (0,0) -- (16.5, 0); \begin{scope} \clip (0,0) rectangle (4.5,4.5); \draw (2.25,0) circle(2.25); \draw (0,0) -- (4.5,0); \end{scope} \begin{scope} \clip (6,0) rectangle (10.5,4.5); \draw...

Hello, So we are designing a turbine. We have a shaft that receives 710W / 13.6NM / 500RPM from the runner and we are going to find a diameter with safety factor of 3. Take the following information regarding metal: Aluminium 6061 Tensile strength 115 MPa Yield strength 48 MPa Shear...

How can I calculate diameter of a molecule

Source: fobasics.blogspot.com Source: scirp.org As it is shown in the first pic above that the mode field diameter is defined as the mode field decreases to 1/e (in intensity 1/e^2), if I take the mode field and subtract the core's diameter then I divide it by 2, should I get the penetration...

Can anyone help me in what assumptions I can make and how to justify them for when working out diameter of the molecule in part b) of this question? You can see the method that I have used in my workings but how would I explain it in words? I obtained the diameter to be 0.13 nano metres which...

Hello. I have figured out a few things about ST-type exchangers and I intend to build a reactor with this new knowledge. I have a rather... small problem. So I searched for shell diameter correlations given the pitch and number of tubes and I found this from a writeup: Apparently, it's from...

Mentor node: Added code tags From=menu('select:','c', 'g', 'a', 's:'); This is part of my code and I'm not coming up with anything close l=input('input wire length') %current copper=12.5572...

Hello. My attempt at the solution is as follows: l = 160m Q= 300 ls-1 R= p2/p1= 6+1.01/1.01 = 6.94 (2dp) d = Unknown Pressure drop = 0.3 Bar 0.3 = 800*160*300^2/6.94*d^5.31 0.3 = 1.152x10^10/6.94*d^5.31 0.3 ( 6.94*d^5.31) = 1.152x10^10 6.94*d^5.31 = 1.152x10^10/0.3 d^5.31 =...

I have attached an Excel-worksheet in which the problem should be clearified. The problem concerns the calculation of the bending moment acting in a pin in double shear, experiencing a certain load from a hydraulic cylinder. The plate thicknesses should be taken into account. Specifications and...

Hi! I would like to know how to exactly calculate required wire diameter? For example, here I found this calculator on internet: https://www.solar-wind.co.uk/CST.html . It takes acceptable loss, volts, amps, and cable length for arguments. It specifies Vdc. Would it be different formula with...

If particle accelerators with circumference of the Earth could be built (imagine around the world). How many TeV can it reach? Maybe new physics can occur at 2000 TeV. I heard the US nuclear arsenals costs 2 trillion dollars. Worldwide, the total costs of all nations nuclear arsenals may reach...

I'm trying to determine if a certain bicycle tire size will fit my bike, and that determination is based on the inflated diameter (or width) of the tire. As such, I'm trying to come up with a formula that will give me the diameter of a bicycle tire as a function of the tire's carcass width and...

According to this link (https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/collisions.htm) the LHC achieves a beam waist diameter of approximately 64 microns. What limits them from getting a tighter focal point? Are lower energy beams easier or harder to focus tightly?

Summary: Looking of someone to double check my work on this design issue. I am posting this here because I am no longer a student, but it is similar to a simple homework problem Problem: I am designing a rubber-band like product for a client. He wants to take a durable rubber band and stretch...

Hello, How to determine the pulley diameters? The only know factors are listed below. The smaller pulley is attached to a motor that drives the belt drive system. The bigger pulley is driven and has a lifting force of 45N. Known factors: Motor: Pololu 70:1 37Dx54L mm 12V...

I have found plenty of information about the radio source Hercules A. Its large radio jets are 1.5 million light years long from end to end, the supermassive black hole that produces Hercules A is 3 to 4 billion solar masses, and the black hole exists in the center of galaxy 3C 348. However, I...

M1(50,000)/q (0.4) - M2(50,000)/q (0.4) = 0.025 Is there a special charge for singly charged ions?