Strength Definition and 1000 Threads

I am currently installing some sail shades in my back yard. The manufacturer is callin for 6" tube steel supports but I believe that 4" tube steel filled and compacted with concrete will provide more strength and resistance to buckling. Obviously I am concerned about price but want to do a great...

I am working on an engineering project in which I am mounting an electromagnet onto a small RC robot. The link for the electromagnet is here http://www.mpimagnet.com/catalog.asp?prodid=670540&showprevnext=1 I was wondering if there was any way to calculate the force exerted by the magnet on a...

I have completed the force column in the table however I am not sure what the question is asking me for the field strength calculation. am i to use the 25μC charge or the 8μC charge in the formula 1/4∏ε x Q/r^2, this may be obvious to someone with more experience of these questions, Thanks

http://s3.amazonaws.com/answer-board-image/2924bffb-da01-4543-9697-b67da02e5a5a.jpeg The picture above shows four square regions. Each of the four regions may have its own uniform magnetic field. If there is a uniform magnetic field in a region, the field is directed either into or out of the...

I've looked everywhere and can't seem to find any information. Would someone be kind enough to point me to some literature?

Hi all, i have heard a lot of signal deterioration. so i just wanted to understand if i send a pulse let us say of some 5V and measure it using an oscilloscope and send it through a very lengthy cable and measure the same signal with an oscilloscope can i find that the amplitude of the signal...

Homework Statement The armature of an ac generator is a circular coil with 49 turns and radius 3.1 cm. When the armature rotates at 382rpm, the amplitude of the emf in the coil is 17.0 V. What is the strength of the magnetic field (assumed to be uniform) ? Homework Equations E = N.n.phi...

Hello, Suppose there are two conductors carrying currents. One of them is bare conductor and the other has insulation. Now magnetic field will be created around them due to the current flow through them. What will be the condition of magnetic field strength around them? They have same field...

I need to calculate strengths of welds / welded joints. Could you point me to a handbook or website? I will be a bit more specific. The welds are fusion welding w/o any filler materials and the materials to be welded are thin strips of stainless steel (thickness 5/1000 in)

Homework Statement The strain hardening behavior of an annealed, low‐carbon steel is σ = 100,000ε0.2 If a bar of this material is initially cold worked 20%, followed by additional cold work of 30%, determine the probable yield strength of the final bar. Homework Equations σ=κεη...

I am trying to make a crude coil gun. I remember that if I run current through a coil of wire, it generates a magnetic field according to the right hand rule. Will the inductance of the coil of wire greatly affect the strength of the magnetic field, or is it mainly due to the strength of the...

I want to apologize ahead of time for my apparent inability to get LaTeX to display properly. Homework Statement λ = 3.8 x 10^(-6) C/m R = 32m r = magnitude of the hypotenuse (the book's convention, a poor choice IMHO) r = \sqrt{R^2 + x^2} k = 8.988 x 10^9 P:(0,-32) cosθ = x/r a→∞...

I have a poor physics book that doesn't really explain things easy. My book states that Strong force - 1 Electromagnetic force - 10^-2 Weak force - 10^-6 Gravity - 10^-43 This is the "relative strength between the 4 forces" is what my book says. But what does that mean? Is there...

Homework Statement Q. A metal sphere of radius 20 cm carries a positive charge of 2.0 μC. a. What is the electric field strength at a distance of 25 cm from the centre of the sphere? b. An identical metal sphere carrying a negative charge of 1.0 μC is placed next to the first sphere. There...

Hi guys I have a general query regarding Rubber O-rings. For an application , say seal between 2 mating flanges of pipes ,with water pressure say about 10bars, How exactly does the hardness of rubber effect the the sealing? Is there a direct relation between hardness & strength ? Can some...

Dave made a comment about curvature being a variable when determining strength of a material. I was wondering how curvature does affect strength in structures/materials. I know that "the more circular an object is the stronger it will be" is common knowledge. I am looking for something more...

I don't get the following passage from my textbook. Why can't the magnetic force be measured? I don't see why there is no unit for p. If one pole of a long, thin bar magnet is placed in the vicinity of one pole of another long, thin bar magnet, Coulomb’s magnetic force law states: The...

Hi Atoms are closer in FCC. Does it imply high bond strength? It does imply low bond energy.

Homework Statement How much force is required to punch a hole ½ in. in diameter from a 1/8 in. thick steel sheet of shearing strength 4x104 psi. Homework Equations Shearing Modulus = Pressure/Shearing Strain Pressure = F/A Shearing Strain = DistanceSheared/Length-to-be-sheared...

Say we could slowly vary the strength of the strong force. What would happen to the "size" of proton if the strength of the strong force tended to zero and infinity? Thanks for any help!

What is the process called of heating alloys to Hightemperature 10,000f+ and making them many times there normal strength? do most uivercitys have such a machine? I read about it years ago in New scientist magazine, any help would be great Andrew Perry

I know that I should do my homework, but I lost all my notes because of the flood brought by "Sendong" a storm in the Philippines. I just need the equations to be used to solve the problem that was given to us. So here it is: A parallel plate capacitor has a capacitance of 7MF when filled...

I am building a DIY backyard zip line - total length is 175 ft, starting anchor is a steel pole (6 inch diameter) - 21 ft long, I plan to bury in lots of cement about 4 ft deep - cable will be attached near the top, no guy wires planned, I will "board" the seat on a tree fort near the top of the...

Inside a black hole singularily, the center is pulling spacetime to it, but because the spacetime fabric inside and outside the event horizon are connected... it doesn't shear or break. But during a Big Crunch, the entire spacetime of the universe would be sucked back into the singularity and...

Homework Statement 2 point charges are situated 45nm apart in a vacuum. Charge A is +8μC and charge B is -25μC. X is a point 8nm from A. Calculate the electric field strength at point X only due to A (Ans is 1.2 x 10^9 N/C) Calculate the overall electric field strength at point X due to...

I am in the fourth year of an MPhys and feel a PhD is the best way to further myself. I want to apply to groups that specialize in the theory and implementation of computational modelling. I would prefer this to be a group with a wide range across several branches of Physics as opposed to a...

I am unsure of this matter and so I am curious, do stronger metals more than likely have higher melting/heating points? Does a metal that takes more force/pressure to break or snap have a higher melting/heating point as well? Do metals/alloys like steel or titanium have higher melting points...

Hi everyone. I have a simple doubt related to magnetism and inspired by the Bollywood movie 'ROBOT' staring Rajnikant. In the spectacular chase scene where Chitti(the robot) is trapped on a bridge with Aishwarya Rai( the heroine of the movie) and are surrounded by multitudes of policemen, he...

Hi, Four point charges of equal magnitude are held at the corners of a square. The length of each side of the square is 2a and the sign of the charges are the following: Two positive charges on the top two corners of the square and two negative charges on the bottom two corners of the square...

Homework Statement In the course of the above research, they discovered that this spider silk has an ultimate strength #or tensile strength of 1850mPa (see 11.4 in University Physics). Tensile stress is a measure of the pressure in an object when it is stretched. Tensile strength is the...

In the course of the above research, they discovered that this spider silk has an ultimate strength #or tensile strength of 1850mPa (see 11.4 in University Physics). Tensile stress is a measure of the pressure in an object when it is stretched. Tensile strength is the maximum tensile...

I have always loved math and have done independent theorem-proving and research. However, I have had absolutely no olympiad training but it seems that the math olympiad is quite important in applying to universities. I have started to do some of the questions myself and find that I progress...

hi, great forum. i have searched the internet for 2 days to figure out the following, but with no luck. question, i am going to remove my diesel engine which weighs 800lbs and bolt it to an engine stand. i will be using 4 hex bolts with dimensions, 3 1/4'' long, just over 1/2''...

Homework Statement How do I calculate the Field Strength if I know the Potential? Homework Equations E = -\nablaV V = Electric Potential E = Electric Field Strength The Attempt at a Solution There's a problem in which I calculated the Potential, it's constant however. So according...

I've recently attempted to calculate the force of repulsion between two neodymium magnets. The problems arise fairly early when I don't know how. I know about ampere's force law and all that, but I couldn't find an equation concerning permanent magnets. Obviously, two magnets with rectangular...

I'm looking at redesigning a hydraulic solenoid valve with the aim of reducing the package size. The solenoid coil is by far the largest component of the device, with about 4000 coils arrayed in about 90 layers stacked on top of each other. I'm wondering if I can reduce the size by removing some...

I am curious to know using scientific information what color lightsaber is the strongest? I have done some minor research and cannot figure it out on my own. I have come up with that violet produces the highest frequency while red produces the lowest frequency. Using Planck's Law E=hv I gather...

Does anyone have any empirically based equation for estimating torsional shear strength of a tube made from a given steel. I've seen "estimates" ranging from 57% UTS to 75% UTS, but nothing empirical. I'm open to anything based on UTS, a given offset strength, or JAEL yield. Thanks!

Homework Statement what is the gravitational field strength on the surface of a star that has a radius of 5.0 x 10^6km and a mass of 6.0 x 10^33 kg Homework Equations i tried the F=G MM/r^2 The Attempt at a Solution answer was rly weird and off

Homework Statement Two spacecraft carrying identical pendulum gravity meters have landed on Mars, one at the equator and one at the North pole. Over a fixed period of time the pendulum at the equator is observed to oscillate 250 times compared with 251 times at the pole. Calculate the...

Hello all, Thanks for potentially allowing me to waste your time with a simple question. I am designing a collapsible photo booth and need to know that the aluminum tubing I intend to use is durable/strong enough for both the repetitions of setup and teardown and the weight to be supported...

Background info: This is for a trebuchet I plan on building. Obviously lighter is better especially for the throwing arm which is why I need your help in figuring out that problem, so I can get it as light as possible without it having even a remote chance of failing. If there's information...

In stenger's book he claims that the ratio between gravity and the electro magnetic is not 1039 Let me know if you think he's right Note that N1 (ratio of EM force to gravity) is not a universal number; it depends on the charges and masses of the bodies you use in the calculation. For an...

I have tablet phone samsung galaxy tab... when I check the signal strength, it shows -82 dbm... I thought it is produced by the Signal PA (Power Amplifier) on the PCB... According to what I know, the signal from the handphone is so weak to reach the nearest terrestrial station on the...

What are the factors that determine the strength of an Ionic bond? Taking the example of LiF and K20, why does LiF have a stronger bond strength?

Problem: A +11 nC charge is located at the origin. Question: What is the strength of the electric field at the position x,y (-5cm, 5cm) ? I would think you would do this but when I try it I get the wrong answer for x-axis - E=k|q|/r2 For y-axis - E=k|q|/r2 Then \sqrt{}Ex^2 + Ey^2

I had a lab to do for Physics, and we used a variable voltage source and an electromagnet with 60 turns of copper wire. What is the equation to use to find the magnetic field strength B using relative permeability of a soft iron core? i cannot find this equation anywhere... plus, what is the...

Lattice Constant: 7.956A – 7.936A Density: 3.696 – 3.691 g/cc Form: Polycrystalline Melting Point: 2150°C Young's Modulus: 46.9x106 psi Shear Modulus: 18.9x106 psi Poisson's Ratio: 0.24 Hardness: 1850 Kg/mm2 (Knoop Indentation, 200g load) Fracture Toughness: 2.0 MPa-m1/2...

gravitational field strength problem-urgent help needed Homework Statement Moon has a radius of 1740km, Mass of 7.35 x10^ 22kg, grav field strength of moon= 1.62Nkg^-1, distance from Earth to Moon is 380000km G=6.67x10^-11Nm^2kg^-2 The Moon's gravitational pull on the Earth causes the...

Hey! I stumbled across this problem while reading Wald's "General Relativity", but it belongs to Electrodynamics. In problem 3 of chapter 6 one has to find the general form of a static, spherically symmetric Maxwell tensor, which is clearly F_{ab}=A(r)(dt)_a \wedge (dr)_b+B(r)r(d\theta)_a...