Strength Definition and 1000 Threads

  1. S

    Strength of magnetic field on "eBay electromagnets"?

    How strong, approximately, is the magnetic field, on a powerful electromagnet, that you buy on eBay, that can lift, say, a 100 kg?
  2. E

    Replacing lumber with equiv strength steel/aluminum. Sizing?

    Hello, I'm in the design phase of a greenhouse building and am tossing around the idea of not using lumber. I have put up many stick built structures but am afraid the humidity will rapidly decay a conventional pine/fir. And I want to avoid pressure treated if possible Based on a roofing...
  3. R

    How to work out the tensile strength in pounds

    Hi to all. I have a raw material certificate of drilling pipe - there is a YS=863 N/mm2. I would like to know what is the maximum weight in pounds this pipe can withstand.
  4. AryaUnderfoot

    Understanding Ligand Strength: [Cu(H2O)6]2+ to [CuCl4]2-

    Homework Statement From what I've read, [Cu(H2O)6]2+ when reacts with concentrated hydrochloric acid, the chloro ligand will displace the aqua ligand and form [CuCl4]2- Homework Equations [Cu(H2O)6]2+ + 4Cl- <--> [CuCl4]2- + 6H2O ( <---> means reversible reaction, I don't know how to type it...
  5. A

    The yield strength at temperature SA-789/SA-789 М

    Hi! Could you help me to find the yield strength at temperature SA-789/SA-789 М.
  6. DiracPool

    Relative strength of E and B fields in EM radiation

    I think the equation for the relationship of the E (electrical) and B (magnetic) fields in electromagnetic (EM) radiation is E=Bc, where c is the speed of light. I think this is correct, but what does it tell us? On it's face, it looks as though the B field (of a photon, say) is...
  7. ichabodgrant

    Size of specimen and compressive strength of concrete

    Hello everyone. I have a question about compressive strength of concrete. It is said that (in my country) 150 mm x 150 mm x 150 mm concrete cube is used for concrete testing. Someone asks me why 100 mm x 100 mm x 100 mm is not used. In fact, I know that sometimes it is allowed or even preferred...
  8. E

    Magnetic field strength at point P around a solenoid

    I have a solenoid, Length L, number of turns N, ampers I Radius R I have a Point P(x,y,z) anywhere around said solenoid. How can I calculate the field strength at point P, note it is OUTSIDE the solenoid, and could be anywhere outside. Assume the origin is the center of the solenoid, let's...
  9. P

    Flexural strength of triangular prism

    Hello forum, could someone share a formula to calculate the flexural strength and flexure modulus of a beam with a rounded triangular cross-section? Namely triangular crayons, which is rounded on the edges. Assuming that the triangle is equilateral. [FONT=Times New Roman]...
  10. HelloCthulhu

    Diamagnetism and Hydrogen Bond Strength

    I've read a few papers regarding the effects of a uniform magnetic field on water solutions, but I'm a complete illiterate when it comes to deciphering the jargon. So far, many papers confirm that a uniform magnetic field strengthens hydrogen bonds and can increase the redox potential. I've...
  11. M

    Strength of materials/Max bending moment

    Homework Statement It's been a while since I've done this, it's essentially a strength of materials problem in my mechanical analysis class so I haven't worked problems like these in quite a a while. I'm fairly confident I've done it right however I was hoping someone might be able to confirm...
  12. darida

    Components of The Electromagnetic Field Strength Tensor

    Source: http://gmammado.mysite.syr.edu/notes/RN_Metric.pdf Section 2 Page: 2 Eq. (15) The radial component of the magnetic field is given by B_r = g_{11} ε^{01μν} F_{μν} Where does this equation come from? Section 4 Page 3 Similar to the electric charges, the Gauss's flux theorem for the...
  13. S

    Disc reach ultimate material strength by spinning too fast

    So, I am watching this show about airline crashes and apparently, a A380 has gone down because the speed limiter on a spinning engine rotor broke, and the part spun so fast its ultimate yield strength was reached and the material shatterted. Thats got to be one really fast spinning rotor! But...
  14. R

    Unraveling the Stress-Strain Curve: Find Young's Modulus & Yield Strength

    Homework Statement The figure shows the stress-strain curve for a material. The scale of the stress axis is set by s = 280, in units of 10^6 N/m2. What are (a) the Young's modulus and (b) the approximate yield strength for this material? Homework Equations E=stress/strain The Attempt at a...
  15. 1

    Electric Field Strength Question

    I already posted this, but it was on the wrong section. This is from the 2009 HSC exam. (I'm in Australia) I checked the answers and found that electric field strength was E = 100/0.10 = 1000V/m My question is, what would the electric field strength be if the positively charged plate was...
  16. Murdock

    Calculating field strength of an electromagnet

    I would like to build an electromagnet to accelerate electrons into a circle (a precursor to a mass spectrometer). I would like to calculate the field strength, but I don't know how because I would like to wind it out of aluminum strap salvaged from a welder, and I can only find formulas for...
  17. A

    Control strength of permanent magnet

    How to control magnetic field produced by a permanent magnet which is being induced on to a coil ?
  18. P

    Electric field strength from x=-a to x = a

    Homework Statement I attached a file. Numbers 10 and 12. Homework Equations kQq/r, kQq/r^2 The Attempt at a Solution I am confused about this problem. Shouldn't the electric field strength be 0 when x = 0? The charges are opposite and adding two opposite vectors with equal magnitude should...
  19. Baluncore

    What is the effect of permanent magnet strength in generator

  20. SquidgyGuff

    Distance independence of electric field strength

    I was just wondering why the strength of the electric fields of insulating surface charges like sheets and shells aren't dependent on the distance from the charge according to Gauss's Law?
  21. T

    Can I elevate a bed by 4 inches with PVC and sleep on it?

    Hi everyone, it's my first post! I need to elevate a bed by 4 inches for a while. I did some work on this problem already. Here's all the information I used to reach my conclusion: expected total weight with mattress and occupants = 220.92200 kilograms bed weight = 54 kg = 54,000 grams =...
  22. B

    Formula of Average Magnetic B Field Strength of Large Conductor

    Any one knows how to calculate the magnetic B field strength at a distance from a Large Conductor ? Do we go by average ? thanks
  23. B

    Heat affect on sealing tape adhesive strength

    There's a reel of material which has splices connected by regular transparent sealing tape. The bobbin has to be heated for manufacturing. Do you think the heat of up to ~60C degrees could have an affect on tape adhesives?
  24. Corey Bacon

    Electric field strength between two disks?

    Homework Statement Two 3.0 cm diameter disks face each other, 1.9mm apart. They are charged to $$\pm 16nC$$. (a). What is the field strength between the disks? (b). A proton is shot from the negative disk toward the positive disk, what launch speed must the proton have to barely reach the...
  25. P

    Strength of container for vacuum freeze drying

    I have read that freeze drying is the best way to salvage wet books (http://www.ccaha.org/uploads/media_items/technical-bulletin-salvaging-books.original.pdf). However, freeze dryers run in the thousands of dollars, and I don't know anyone who has one I can borrow. Solution: make my own! I...
  26. E

    Difference in strength between extrusions and sheet metal

    Hello, How do I take into account the difference in stiffness when fabricating a part (for example, an L-bracket) from sheet metal or using an extrusion? In particular, where I work, it is "common knowledge" that extrusions are stiffer. How do i factor this in the stress and strain...
  27. F

    Calculating field strength mV/m at distance d - check me

    it's been awhile for me so check if I'm remembering this right... Thanks. electric field strength is inversely proportional to distance squared... right? So if the electric field strength is 1,000 mV/m at 1 meter then the following is true... right? km______mV/m________ the math 1________1000...
  28. Mihai Ilie

    How can I calculate the strength of a beer can / soda can?

    Homework Statement I am doing a project which involves making furniture out of beer/soda cans but I need to do some calculations for it. I know the can can hold around 52 Kg or even more based on experimental results but is there any way to find out with some formulas? I found it tricky because...
  29. C

    Covariant derivatives commutator - field strength tensor

    Homework Statement So I've been trying to derive field strength tensor. What to do with the last 2 parts ? They obviously don't cancel (or do they?) Homework EquationsThe Attempt at a Solution [D_{\mu},D_{\nu}] = (\partial_{\mu} + A_{\mu})(\partial_{\nu} + A_{\nu}) - (\mu <-> \nu) =...
  30. S

    Maximum stress as percentage of Yield Strength

    Homework Statement Hi guys, I have a question here, which asks me to express the maximum stress from my simply supported beam, which I worked out to be 1.165MPa, to be expressed as a percentage of the Yield strength 95MN/m^2. I also have a follow on from that which asked me how much the...
  31. timtrace

    Tube steel strength - advice on project

    Greetings, may I ask for a bit of help with a steel fabrication project? Pictured below is my design for a trailer-hitch mount to be used with a Harbor Freight tire changing tool. I need help determining the thickness and composition of the tube and plate steel to be used in the project. I...
  32. T

    Calculate gravitational field strength above surface of Mars

    1. Calculate the gravitational field strength at 500km above Mars' surface. Mass of Mars: 6.39 x 1023 kg Radius of Mars: 3.39 x 103 km Constant G: 6.67 x 10-11 2. I used the equation g = GM / r23. To begin with I added the 500km height above ground to the radius, giving 3.89 x 103 km. I then...
  33. A

    Hall Effect Probe for Measuring Magnetic Field Strength

    Homework Statement In a probe that uses the Hall effect to measure magnetic fields, a 11-A current passes through a 1.33-cm-wide and 1.31-mm-thick strip of sodium metal. If the Hall emf is 2.42 μV, what is the magnitude of the magnetic field (take it perpendicular to the flat face of the...
  34. J

    Finding the magnetic field strength

    Homework Statement There exists a current of 5A in the ay direction at x=2m,z=-2m where the ay is the unit vector in the y direction. Find the magnetic field strength at the origin. Homework Equations B = (μI/2πR) * r B = μH The Attempt at a Solution B = (μI/2πr) B= (4π*10^-7)(5)/2π(2) where...
  35. Euler2718

    Solenoid Field Strength - Missing Raduis?

    Homework Statement A long solenoid has 35 turns/cm. With a current of 4.0A, what is the field strength at the core? Homework Equations \beta = \frac{\mu N I}{2r} The Attempt at a Solution I have no idea with the radius is; that's the entire problem statement above.
  36. M

    Wall strength and tension on rope-pulley system

    Hello, My friend needs to transfer construction objects across a pond, came up with this idea of tying a rope between the pond and a big tree then transfer objects through a pulley, I'd like to know how to calculate the tension and will the thin concrete wall withstand the load? Here a diagram...
  37. V

    Magnet strength between 2 magnets

    Hi all, I have two identical magnet which measures 0.6T when I put my gauss meter on the top surface. I configured the magnets as below: I would like to know what should I expect if I measure the strength(Tesla)at the red round dot position? Would it be 1.2 tesla? Please advise. Thank you...
  38. R

    Container stack height on a ship: Mechanical strength

    In the photo of a container ship cargo seems stacked 12 high. I do know that there's lateral supports etc. that are not visible in the figure, yet the vertical load, isn't that transferred downwards to the bottom container? Or is there some way to support the stack at an intermediate point so...
  39. R

    Deriving the electromagnetic field strength tensor

    Just one last question today if someone can help. I'm trying to derive the electromagnetic field strength tensor and having a little trouble with (i think) the use of identities, please see below: I understand the first part to get -Ei, but it's the second line of the next bit I don't...
  40. littlejon

    What is the Strength of the Electric Field?

    Homework Statement Specify the strength of the electric field. Let r = 7.3cm . Homework Equations E1= (k*p)/(r^2+a^2)^3/2 Here k= constant used in Coulomb's law. a= half the length of dipole p= dipole moment = charge x length of dipole. Charge = 3nC and length of dipole The Attempt at a...
  41. George Zucas

    0.2% Offset vs. 0.5% Extension Under Load Yield Strength

    Hello everyone, I have designed a part that should be able to withstand a shear stress of 43 MPa ( give or take). The part will be made of Nickel Aluminum Bronze (CuAl10Ni5Fe4). When I check yield strength values for this material (I'll multiply it by 0.6 to estimate its shear strength), they...
  42. Alexandra7

    Does the equation N = No e¯kt represent Radiation Strength?

    Homework Statement Given that we are working with biological samples of 5 and 10cm, is our assumption that the equation N = No e¯kt represents the radiation strength accurate? Explain. Homework Equations N = No e¯kt The Attempt at a Solution I'm completely stuck but... I believe it...
  43. N

    Maximum Strength, Minimum Weight Material

    which commercially available material has maximum strength but minimum weight ?
  44. M

    Metal bar/tube strength by length and thickness.

    Hello guys I am working on designing somethings and I am using metal tubing. I do not know what type of metal tubing I am going to use this all depends on the math after I work my problem out. I am not sure what formulas to look up or what strength test I need to look up. For example if I have...
  45. R

    Calculating Yield Strength for Dowell Pins

    So how do I figure out if say a part is being made with a .250 round dowell pin at 100,000 yield strength and I want to use a material at 60,000 yield strength how much bigger would I have to make the dowell pin to achieve the same yield strength?
  46. D

    How hard can you push something given grip strength?

    Hello, I was hoping you could solve an argument. We are wondering how hard you can push something. Let's say I have a piece of wood clamped down on a table and I want to push the piece of wood left or right. If the clamp is pushing down on the piece of wood at 100 pounds, I would need 100...
  47. P

    Strength of magnetism and electrism

    hello can you give me some idea of the quantity of magnetism, electrism and forces involved? for example, what is the torque in Nm or the Joules, that I can generate, via a motor perhaps, from a 220V AC motor? I want to know how much magnetism and electrism I need to rotate a disc that poses...
  48. T

    Gravitational field strength of a mass

    A 20 kg mass is situated 4m above the Earth's surface Taking g as 10 m/s2. What are the gravitational field strength and gravitational force acting on the mass? Am I wrong when I say that because the height of the mass ( which is 4m) is too little comparing with the radius of the Earth so that...
  49. P

    Electromagnetic Coil Strength from Moving Liquids?

    I was reading about drift velocity and according to http://amasci.com/miscon/speed.html 100VDC at 1A moving through ~12 AWG wire would produce an electron velocity of 8.4 cm/hr. Since that is incredibly slow I'm curious if a charged fluid (something like the oil used in an oil-based van de...
  50. C

    Solid solution hardening, concentration dependence

    When you add impurity atoms to a material, the yield strength often increases by a process known as solid solution hardening. This is because the impurity atoms create a barrier to dislocation motion. The literature describing this phenomenon dates back to the 1960s with some famous papers by...
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