Ratio Definition and 1000 Threads

Homework Statement I have some strain readings using a rosette gauge, but I want to know how to calculate the poissons ratio for the steel pressure vessel Homework EquationsThe Attempt at a Solution I tried Strain A/Strain B and got an average value of 0.4. But the provided value for steel is...

Hi, I'm learning the basics of plasma assisted combustion so I've been reading up on a few articles related to it. My question is regarding this article http://enu.kz/repository/2011/AIAA-2011-971.pdf Using a setup consisting of a pair of counterflow burners, the composition of the oxidizer...

Hi all, I'm a writer who is not really great at math so I need some help with establishing time rates between different "realms" in a world-setting I'm building for a story. The gist is this: Earth is there with it's normal 1 year = 1 year timeflow. There are two realms where time runs much...

Hello! A two-dimensional beam of thickness S and velocity c (evenly distributed at the thickness) falls in stationary plate and get separated. Calculate the ratio of thicknesses S1/S2 as a function of the angle φ. (see attachment)In my notes there is this solution: Continuity equation: Let...

Hi I have some question...I want to find what fraction of some produced ##D_s^\pm## to decay into ##\tau##'s. I was looking around the pdg and I came across something that confused me. Here: http://pdg.lbl.gov/2014/listings/rpp2014-list-Ds-plus-minus.pdf on page 4 it lists the semileptonic...

Below is a screen shot of a solution to a problem. The part I don't fathom is after the ratio test is applied to the denominator. How can, noting that an+1, (2n-1) become (2n-1)(2n+1) and not just (2(n+1)-1)=2n+1? Thank you in advance

Homework Statement A ball of mass m1 is aligned above a ball of mass M2 (with slight separation), and the two are dropped simultaneously from height h. (Assume the radius of each ball is negligible compared to h.) (a) If M2 rebounds elastically from the floor and then m1 rebounds from M2, what...

Hello guys, I'm currently working on a car simulation just for fun, but I'm stuck... The force to move a car is generated by burning fuel ( to be more percise, diesel or gasolin). But there are more variables: Pressure (i know this because of turbos and such) amount of fuel amount of air (or...

Homework Statement If λCu is the wavelength of Kα X-ray line of copper (atomic number 29) and λMo is the wavelength of the KαX-Ray line of molybdenum (atomic number 42), then the ratio λCu/λMo is close to 1.99 2.14 0.50 0.48 Homework Equations De broglie relation λ = h/p The Attempt at a...

Hello PF! I have a very simple question on psychrometry. I had an argument with one of my professors regarding these two quantities, humidity ratio and specfic humidity. Humidity ratio is defined as mass of water vapor per unit mass of dry air. It's the one you can read from a psychrometric...

Homework Statement 800L/h rated pump 12.6mm outflow pipe. Static head height 1.10m There seem to be no undue turbulence in the flow. Environmental pressure is just atmospheric (1bar) 2. Homework Equations Unknown The Attempt at a Solution I have done the physical experiments which is how...

Homework Statement [/B] This is the question I have (from a worksheet that is a practice for a quiz). Its a conceptual question (I guess). I understand how to solve ratio test problems. "Is this test only sufficient, or is it an exact criterion for convergence?" Homework Equations Recall the...

Hi all, I have a small DC motor which turns at 20 rpm. The shaft diameter is 6mm, giving a circumference of 18.85 mm. What I want to do is get an effective rate of 30 rpm. Can I do this by simply attaching a spool or spindle to the motor output shaft with a larger diameter? If so, would it...

Homework Statement (in picture) Homework Equations V=IZ The Attempt at a Solution So last time I had to do KCL to find voltages, so I want to make sure I'm doing this one right. Can I do voltage division and do Vload/VG? My division would be VG(500<36.87)/(500<36.87 + 60<53.13) But that...

Homework Statement I'm reviewing for a test and working on the practice problems for the ratio test that Pauls Online Notes gives. So here is given problem: Here is his solution for the problem: 2. The attempt at a solution I worked this out before I looked at the solution and I got it wrong...

Hi everyone, I'm currently taking Calc II course and I'm kind of stuck in this ratio test proof thing. Homework Statement http://blogs.ubc.ca/infiniteseriesmodule/appendices/proof-of-the-ratio-test/proof-of-the-ratio-test/ I'm trying to understand the proof, but there are some parts that I...

Homework Statement Why do InP diode has larger peak to valley current ratio as compared to GaAS diode? Homework EquationsThe Attempt at a Solution

my turn to have something answered o0) 1. Homework Statement The problem is to show that Fermat numbers are relatively prime, which I could just look up somewhere but I want to use the mod operator that is used in Concrete Math, which says ##n \bmod m = n - m\lfloor{\frac{n}{m}}\rfloor## So if...

Homework Statement (a) What are the branching ratios for EM decay only? (b) What does this reveal about the strength of strong interaction? (c)What are the relative rates of decay? Homework EquationsThe Attempt at a Solution Part (a) [/B] For EM-only decay, the branching ratio would be...

Homework Statement Two parallel-plate capacitors have the same plate area. Capacitor 1 has a plate separation half that of capacitor 2, and the quantity of charge you place on capacitor 1 is six times the quantity you place on capacitor 2. How do the two Potentials differences of the capacitors...

Homework Statement Part C: http://imgur.com/mFlXGZs Homework Equations Power = τω The Attempt at a Solution P1/P2 = τ1ω1/τ2ω2 = (T1/T2) * (ω1/ω2) T1/T2 is found in part B: r1/r2 (ω1/ω2) = vr1/vr2 (velocities are the same) = (r1/r2) (r1/r2)*(r1/r2) = (r1)^2/(r2)^2 The answer is 1.

Homework Statement An object is located a distance d above the surface of a large planet of radius r. At this position, its true weight is one percent (1.000 %) less than its true weight on the surface. What is the ratio of d/r? Homework EquationsThe Attempt at a Solution so if something...

I'm designing a differential mount and am trying to wrap my head around the pitch loads the mount sees. My question is with a 1000 Ft/lb input torque will the ring and pinion ratio effect the torque that the mount must resolve? The differential is a sub-frame mounted IRS assembly, Nissan R230...

Homework Statement A 10 gram silver sphere is charged until it acquired a charge of -1.2 coulomb. Find ratio of number of electron to number of proton in spere. Given that silver atomic weight and atomic number 107.87 and 47 Homework EquationsThe Attempt at a Solution first i calculated extra...

1. The problem statement: A ray of light is incident on a concave mirror. It is parallel to the principle axis and its height from principle axis is equal to the focal length of the mirror. the ratio of the distance of point B to the distance of the focus from the center of curvature is( AB is...

Homework Statement A vehicle having wheels with a diameter of 58cm, is powered by motors that have a maximum speed of 6024 rpm. Each motor is coupled to the wheel using a gear mechanism as shown in figure 2-14. Calculate the required gear ratio if the vehicle's maximum speed is 190.2 km/hr...

Homework Statement A body is dropped from certain height H. If the ratio of the distances traveled by it in (n-3) seconds to (n-3)rd second is 4:3, find H (take g= 10 m/s²) (answer: 125m) Homework EquationsThe Attempt at a Solution I did this way but I came to a dead end... To find H, s= 1/2...

Hello PF'ers, I am doing an unbinned likelihood analysis where I am analyzing the ratio of two spectra: \[ \frac{S_{1}(E)}{S_{2}(E)} = F(E) \] and each spectra, \[ S_{1}, S_{2} \] has its own data set. My first idea was to take the function, \[ F(E) \] and divide by the integral of...

Hey all, I'm new here and hoping to enjoy glorious physics with you all! I have a problem and a question; the problem is I don't know much about electromagnets and want to build something rather involved using an electromagnet. XD The question shall be explained.. General Concept: I'm going...

Homework Statement The ratio of nitrogen to oxygen at sea level is 4.0:1. Use Laplace's law of isothermal atmospheres to calculate the same ratio for 3255m above sea level Assume that T = 273 K Homework Equations P_fN2 = P_iN2 * e^-\Big({\frac{M_N2 g}{R T}}*h\Big) P_fO2 = P_iO2 *...

Homework Statement A Gas is in a Volume V0 = 1 Liter at Pressure p0 = 3 bar. Isochoric Heating using the Heat Q1 = 182 J, the pressure raises to p1 = 6.34 bar. Gas is reset to inital state. Isobaric Heating using the Heat Q2 = 546 J, the Volume increases to V2 = 3 Liter. Calculate Cp/CV...

Homework Statement Homework Equations v=fΛ v=√(T/μ) The Attempt at a Solution I know I'm supposed to make an attempt, but I can make heads nor tails of this. Are they changed in a constant ratioo? Does the tension come into play? The answer given is 0.16m

Seasons' Greetings. I have been asked to express the reaction of H2N(CH2)3NH2 with HOOCCH2(C6H4)CH2COOH in a stoichiometric ratio. Would appreciate some guidance, not with the equation in particular, but the semantics of it.wirefree

I've heard of it, but unfortunately, I don't really understand in depth what it actually is. Could someone please help me with this? Thanks.

I have a conceptual misunderstanding it seems. Poisson's ratio is the ratio of elastic strain deformation of the transverse and longitudinal components. That being said, if I were to induce thermal stress (heating up) to a rod by keeping its ends (longitudinal component) rigid, would there be a...

Homework Statement The chemical analysis of a fuel is determined to be: 84.60 wt% C, 11.12 wt% H, 1.95 wt % S and the balance, inerts. The fuel is consumed in a steam generating furnace with 33% excess theoretical air. The air is preheated to 190degreesC and enters the furnace at a gauge...

Mechanically reconditioned sand weighs 8.50#/gallon Thermally reclaimed sand weighs 8.89#/gallon A mix of these two kinds of sand weighs 8.78#/gallon What is the % thermal and %mechanical in the mix? I work in a foundry and we feed these two types of sand into a hopper that feeds a mixer. It's...

Hello everyone. I have to describe is the Severn Bridge, a suspension bridge [FONT=Arial]spanning the River Severn and River Wye in England. I have found almost all the measurements, except for one: the sag span. I could only find the sag ratio (1/12) but I need to convert this ratio to meters...

Hi, last week I read Rabi's paper "The Molcular Beam Resonance Method". This paper contains the basic idea of the oscillation which we call "Rabi Oscillation" as many of you guys know. However, at the end of this paper, Rabi calculates nuclear magnetic moments of Li (atomic mass 6), Li (atomic...

Homework Statement I have a problem: So one tank is pressurised and then a pipe connecting this tank to a smaller one is opened so air can flow into the smaller tank. You then wait for the pressure to settle and read some pressure for each cylinder values. I need to find two ways to measure...

Why do math professors always say that dy/dt is NOT a RATIO? I’ve sat down and really analyzed it and I can only conclude that dy/dt is a ratio between the function delta value y and the corresponding delta t at ANY point on a continuous function. Here is why: (This is a bit of a mix of...

Homework Statement ∑ x2n / n! The limits of the sum go from n = 0 to n = infinity Homework EquationsThe Attempt at a Solution So I take the limit as n approaches infinity of aa+1 / an. So that gives me: ((x2n+2) * (n!)) / ((x2n) * (n + 1)!) Canceling everything out gives me x2 / (n + 1)...

Homework Statement Poisson's ratio v is the negative ratio of the transverse strain to the axial strain. For an incompressible (density doesn't change), homogeneous (everything is the same molecule), isotropic (it doesn't matter which direction you pull or push on it, it will act the same way)...

On the subject of our 'finely turned universe', I have read that the proton-electron mass ratio can not deviate more than 1:1037. In other readings, the allowable deviation was stated as 1% ("If the neutron were very slightly less massive, then it could not decay without energy input. If its...

Hi, I have some experimental data and I am interested to use this data to calculated modulus of elasticiy (young's modulus) and Poisson's ratio. The material for which the data is given in an anisotropic material, therefore I need to calculate modulus of elasticity and poisson's ration is x,y...

Hi, I have some experimental data and I am interested to use this data to calculated modulus of elasticiy (young's modulus) and Poisson's ratio. The material for which the data is given in an anisotropic material, therefore I need to calculate modulus of elasticity and poisson's ration is x,y...

Does altering Gear Ratio improve efficiency (loss of energy as heat while converting EE to ME) of a machine? I also read online that having higher gear contact ratio improves the efficiency, but I really don't understand how.

greetings...! I need some correct info for a project I am working on... this site looks like it may well be able to help me . the problem is as follows; I have a 12'ft. wheel that I need to turn at a maximum of 60 rpm. the shaft from the power supply turns at 2300 rpm. what would be the gear...

Hi all! My question is as follows: The Chinese e-commerce company Alibaba Group floated its share in the biggest IPO in US history. Alibaba Group priced its shares at 68 dollars raising 21.8 billion dollars and valuing the company at 167.6 billion dollars. The IPO prospectus notes that Alibaba...

Hi all, I'm looking for physical and mathematical explanations for a phenomenon I've noticed when working with rotated material properties relative to an XYZ coordinate system. For certain rotations (~40 to ~50 degrees) about a single axis the S12, S13, or S23 components of the compliance...