Strength Definition and 1000 Threads

Is a hydrogen on an ethanol more or less positive than on a water molecule. I think the hydrogen is more positive on a water molecule, but I still don't understand why? Could someone help me figure this out... please and thank you :wink:

I am designing a stepper motor, and I need someone to check my calculations. The results seem impossibly low... Suppose the vehicle driven by the motor is already up to speed. The force needed to maintain that speed are, say, 100 Newtons. At the speed, the stepper motor performs 15,000...

I am trying to find an equation that tells the strength of a magnetic field a given distance away from the source. It would be very helpful if all terms are defined, since the internet is notorious for not saying what variables mean. Gracias

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Hello and thanks in advance for any help given. I have attached a drawing of sorts (please excuse the novice attempt) for a design I am working on to pivot a 40"x60"x1.5" item framed mirror) using an actuator. My question is specific to the part of the design marked "B" in red. Basically this...

Homework Statement A 14.2 cm - diameter circular loop of wire is placed with the plane of the loop parallel to the uniform magnetic field between the pole pieces of a large magnet. When 3.10 A flows in the coil, the torque on it is 0.135 m N. What is the magnetic field strength? 2...

What will fail if the aluminium impeller rotating at 7500 rpm and powered by 355 kw motor strikes against the stationary 10 mm thick ms plate welded at both the ends having length of 350 and width 200 mm and impeller blade is 12 mm thick. I am confused in first glance we think that blade will...

Hi, I've just completed a prac, where a beam was placed into a solenoid with a current flowing through it, causing a force to exerted down and I balanced out the force by placing weights on the other end in the effort of calculating the magnetic field strength. Anyway, one of the short answer...

Hi, I have some very basic question that I've been struggling to find the answer to and before I go and buy some magnets to do some test of my own I thought I'd ask here: Do two magnets of different strength repulse each other at the same strength, or does one repulse the other more...

Hi, I am a newby to all of this, can't find any good answers on the internet, hope someone with experience can help! If I have a solid steel pole with a length of 50 cm, hang this from a roof, and want to hang a 7 kg object from this pole, how thick does the pole have to be? If I reduce...

A bar of length 4m when used as simply supported beam and subjected to a uniform distribution load of 30kN/m over whole span, deflects 15 mm at the center. Determine the crippling loads when it is used as a column with following end conditions. a)both ends pin-jointed b)One end fixed and other...

OK well, this isn't a question as such, more a conceptual thing... The formula, B=(Weber)/(Area) gives the magnetic field strength, B in Tesla... . But when I rearrange in terms of magnetic flux, it's obviously (Tesla) X (Area). My question is, how is the flux (lines of force) defined by the...

Hi, There is clearly an analogous relationship between Yang-Mills theories and LQG, for example the covariant derivative, the field strength tensor, the field and its conjugate momentum etc... I am wondering how far this analogy extends. Specifically, is the Lagrangian for LQG the...

Homework Statement A medium carbon annealed steel rod has a rectangular cross section and must cope with a tension of 3 tonnes. The thickness of the rod is 15mm. Calculate the size of the cross section. Homework Equations ? The only formula I know with CSA and force is: stress = Force...

R at B = 5.0625 R at A = 8.5kN-5.0625kN=3.4375kN x/0.9375=(0.5-x)/4.5625 x=15/176 but moment near x there i get different from both side: from A = 2.431kNm from B = 2.346kNm is there something wrong?

Hello can someone please tell me the difference between stiffness and hardness and between strength and toughness? thanks

Homework Statement lectric fields of varying magnitudes are directed either inward or outward at right angles on the faces of a cube, as shown in the figure. What is the strength and direction of the field on the face F? (The cube does not contain any charges. Take EA = 13 N/C, EB = 26N/C...

Homework Statement Here are a bunch of questions that I've attempted. I feel fairly confident with my answers, but I just wanted to make sure :) Thanks! a) calculate the synchronous speed, amount of slip and the percentage slip in a typical aircraft a.c., four pole, 400hz induction motor...

Homework Statement You have a co-axial cylindrical capacitor placed in vacuum. The two co-axial cylinder tubes are made of copper. The outside tube radius a1 and inside tube radius a2, with overlapping length L; both tubes have a thickness of t. Say, the capacitor was designed to withstand 5...

I was looking at bolts strengths on this chart (bottom of page) http://www.derose.net/steve/resources/engtables/bolts.html#largebolts and saw that for a 1/4 unf the bolt shear was around 370 but the chart below it listed it at 2700. Why is that?

Are these two things the same? I'm looking at bioabsorbable copolymers with similar properties to the human acetabular labrum, but I can only find tensile strength values for the copolymers and tensile stress at break for the labrum. I've looked at the definitions of each it sounds like the...

Homework Statement An infinitly long conducting cylinder of Radius R carries a inform surface charge of (lambda per unit length) determine the electric field strength inside and outside the cylinder Homework Equations integral (E.ds)= q/e0 The Attempt at a Solution im not really sure what...

Hello again PF I am trying to find the failure load for a 6061-T6 Aluminum forklift pocket weld with 4043 filler. Can I simply multiply the cumulative throat area by the ultimate yield strength of the filler for this value? I never had any formal education on welds, wasn't sure if I'm missing...

I have to desgin an experiment for physics and and my research question is going to be: How does the cross-sectional area of the solenoid’s coil affect the strength of its magnetic field? This is my hypothesis, my question is if you think the reasoning is valid. I believe I should find it is...

i don't know whether to use the yeild srength or allowable stress to determine section sizes of a beam please help me :) thank you.

Homework Statement A capacitor is formed by two concentric spheres r1= 30 cm and r2=15 cm, with a liquid insulant between them with relative permittivity Er=4. The potential difference between the spheres is 1 kV. Find: 1. capacitance 2. maximum field strength in the gap between the two...

Homework Statement A wire in the shape of semicircle with radius a is oriented in the yz-plane with its center of curvature at the origin (Fig. 28.67). If the current in the wire is I, calculate the magnetic-field components produced at point P, a distance x out along the x-axis. (Note: Do not...

When Calculating Electric Field Strength using Q/kr^3, if the Q is negative is this negative disregarded? If not this would make E around a negative charge, negative. But if a positive test charge (q) is placed between two charges (Q1(negative) and Q2(positive)) then for Q1 (the negative charge)...

Hello, I just read a book reagarding Newton and his laws and had few questions about it. What is Gravitational field strength exactly and what is Newton's universal gravitational constant? Aren't they the same thing? please explain these two concepts simple enough for me to understand and to...

Homework Statement (This was part of an assignment that we had to create, so the question is one of my own, although I'm not quite comfortable with this area, hence why I'm asking for help) Calculate electric field strength of a positive point charge of 1.3x10-7C that is 5.3x10-4m away from a...

Is it true that deforming a ceramic will increases its strength? if yes or no why? Thanks

Hello all - this is my first time giving this forum a try. I've been using another site for a while but it's just too spotty and not enough folks there care to give decent responses, so here I am :) Homework Statement http://img684.imageshack.us/i/27p28.jpg/ What are the strength and...

I am wondering what would happen in the following scenarios? I am not looking for exact numbers, but generalized results. Say I have a rigid buoy that has a volumn of 2 gallons. I have a swimming pool or other large body of water. I have the buoy at the bottom of a ten foot deep pool...

I would appreciate some help in finding data if any is available, on tensile and/or yield strength of W1 water-hardening tool steel in the annealed condition. All data I have been able to find makes reference to mechanical properties in hardened and drawn condition, because that's what you do...

Homework Statement Homework Equations The Attempt at a Solution I let µ be 9, as that's the approximate permittivity of air/ free space. I assumed that as a hat had a subscript y, it ran parallel to the y axis, and worked from there, getting the cross product of the unit...

How do flux meters work ?? On what basis they measure the strength of field please share the link (Urgently required)

Homework Statement So I have done a lab involving how Magnetic Field Strength varies with distance from a magnet. using a magnetic field sensor, some recording software, a meter stick a magnet. From this I gathered the fact that as distance increases magnetic field strength decreases...

A radio tower broadcasts within a 50 mile radius. At a minimum, how many such towers are needed to completely cover a 100 mile radius?

Homework Statement the Hamiltonian of a free particle in an electromagnetic field is, H=H_{free} + H_{int} + \frac{q^2 A^2}{2mc^2} where the free Hamiltonian is just {p^2}/{2m} and the interaction Hamiltonian is, H_{int} (x) = -\frac{q}{mc}p\cdot A + q A_0 Show that the last term in...

I am working with flexible electrostatic adhesive pads. These are similar in many ways to a normal adhesive tape in but the adhesion can be turned on and off electrically. Like many adhesives they are notoriously weak in peel. This bring me to my problem. I am trying to get a qualitative idea...

A friend of mine has a job interview tomorrow with a prestigious company. She is almost guaranteed the job because she's good friends with one of the hiring managers. Her current job has no room to grow, pays below average and has no benefits but she has pretty much made the owner stress free...

Homework Statement An electron in a cathode-ray tube is accelerated through a potential difference of 10kV, then passes through the 2.0cm wide region of uniform magnetic field.What field strength will deflect the electron by 10 degrees? Homework Equations Ki + Ui = Kf + Uf K =...

When I saw that the Feats of Superhuman Strength thread was active in S&D, it struck me that we need a thread dedicated to feets, as well. Personally, my feet smell like roses washed by a spring rain.

Hi, I was wondering what is the relationship between 'diameter size' and the strength to flex a hollow tube... is it linear or non-linear? I'm measuring the flexural load of different hollow tubes (with different diameter size) and looking for a way to normalize the the flexural load data...

Homework Statement Hey everyone, I'm just studying some physics, and came across this question where I don't know why I'm wrong =( It's from Physics (5th Ed.) by Halliday, Resnick and Krane - Chapter 27, Exercise 22 Positive charge is distributed uniformly throughout a long, nonconducting...

Does the magnetic field increase linearly with the number of magnets? For example, will 8 1/2 inch neodynium cubes have the same strength as a 1 inch cube? Thanks in advance

Difference between Electric flux density,electric field strength... I want to know the difference between,electric flux density and electric field strength.Are they the same? And also,there is a magnetic field(measured in Tesla),magnetic flux(in Weber),magnetic flux density(Weber per...

Homework Statement A wire carries a current and consists of three sections with different radii. Rank the sections according to the following quantities, greatest first: (a) current, (b) magnitude of current density, and (c) magnitude of electric field. Homework Equations i =...

In a test that was held many weeks ago.. We were asked whether concentration will affect the strength. The answer given by the teacher is yes.. As based on the concept of pOH... But i strongly disagree and i had a debate with my lecturer. . I said it should be based on Kb or percentage...

Hello, I am working on a project and I came across a question that is a little beyond my skill set. I am designing a support for a roof, and I have the force into the post, the length of the post and I need to determine what pipe I need, size, schedule diamter, etc. How do I go about this...