Strength Definition and 1000 Threads

  1. R

    Electric Force and Field Strength Problem

    Three charges are located on a coordinate plane scaled off in meters. Charge #1 is 5 nC and located at (0,0). Charge #2 is -3.0 nC and located at (0,-.10). Charge #3 is 6.0 nC and is located at (-3,0). a) What is the net force (magnitude and direction) on the charge at the origin? b) What is...
  2. J

    Gravity Acceleration: Is it Proportional to the Strength of Gravity?

    So is the strength of gravity proportional to the speed of acceleration of gravity? So would an object with 2g of gravity have a 19.62 m/s^2 acceleration? I am sure this sounds like a stupid question
  3. M

    Can we determine the NK nuclear detonation strength?

    News reports have it at 4.9 magnitude and a depth of 1 kilometer The USGS appears to have it at 5.1 and the depth is not currently known accurately. http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc000f5t0.php#details...
  4. J

    Find electric field strength between disks

    Homework Statement Two 2.0cm diameter disks face each other, 1.0mm apart. They are charged to -10nC and 10nC. -What is the field strength between the disks? -A proton is shot from the negative disk toward the positive disk. What launch speed must the proton have to just barely reach...
  5. S

    Computing Neutron Source Strength - Your Advice Welcome

    Greetings to all, I know activity for a Am-Be neutron source. I want to compute strenght source in neutrons/s. Yours advices are welcome. Thank you!
  6. T

    Strength and Direction of Electric Field

    Homework Statement What are the strength and direction of the electric field at the position indicated by the dot in the figure? Answer in component form. Homework Equations E=kQ/r^2 The Attempt at a Solution E(+5) = (8.99E9)(5E-9)/(0.02^2) = (1.1E5i, 0j) E(-5) =...
  7. B

    Calculating the strength of a magnetic field in a electromagnet

    hi all, i have just signed up to this site to find some assistance with the above topic. i am building an electromagnetic propagator to study the effects of varying field strengths on the germination of seeds and the rooting of cuttings. it has been many years since i last look into...
  8. W

    What is the strength of the gravitational field?

    Homework Statement What is the strength of the gravitational field on the ground just above the oil deposit? Hint: Consider the missing mass as a sphere with a negative mass. Given: a spherical oil deposit with radius 200m at a centre of depth 2.0km. The density of the Earth's crust is 2700...
  9. C

    Question on strength of materials asked at a phd interview

    Consider a cantilever beam of rectangular cross section made up of two materials steel and aluminium. an axial force is applied at one end. the question asked was which material should make up the upper part and which should make up the lower part of the beam? Could someone please help me in...
  10. C

    What material has the lowest tensile strength?

    kevlar has the greatest tensile strength(yield strength here) in all materials at 3620 MPa , am i correct? and i want to know which material has the least tensile strength(yield strngth)..
  11. S

    Inflate aluminium tube to increase it’s strength?

    I’m designing and hope to build a human powered helicopter (HPH) and am wondering if pressurising a thin walled aluminium tube by filling it with compressed air would strengthen it’s structural properties. Hope this is the right place to post this.
  12. C

    Gravitational field strength between masses

    Homework Statement A mass at a point X gives rise to a gravitational field strength g at point P as shown. An identical mass is placed at point Y x ________ p ______________________ y The resultant g f s is now? Homework Equations g = Gm/r2 The Attempt at a Solution...
  13. N

    Are We Walking on Forces When We Step on Ice?

    When water freezes to ice, it becomes so strong that we can move over it. This freezing takes place of bonding between water molecules, the mass of water being the same. 1. Does it mean that we are virtually walking on forces? 2. Does it mean that forces are more important than mass...
  14. V

    Comparing the Acidity of H2S and H2O: The Role of Hydrogen Bonding

    Which is more acidic H2S or H2O?And why?
  15. A

    Initial yield stress Vs. tensile strength

    Are those the same? if not, how do I calculate the initial yield stress from the tensile strength? all the materials properties I see on the web only specify tensile strength, and I need the initial yield stress as an input on non-linear FEA analysis. Is it possible to extract the initial yield...
  16. W

    Calculating Magnetic Field Strength in a Balanced System

    Homework Statement Homework Equations force = current * length * field strength * sin (theta) current = 5.6 A mass/ length = 80g/m right angles = sin(90) = 1 The Attempt at a Solution i noticed the mass is given in grams, 80 grams to be exact or .08 kg . how would I find the...
  17. W

    Find magnetic field strength and maximum force

    Homework Statement Homework Equations Force = Current * Length * Field Strength * sin(theta) (Force/ Length)/(Current * sin theta) = Field Strength The Attempt at a Solution (.28 N/m)/ (14 A * sin 27 degree) = .044 T or 44mT
  18. snoopies622

    The uncertainty principle and electric field strength

    As my knowledge of an electric field strength becomes more precise, what physical quantity becomes correspondingly less precisely known?
  19. R

    Electric Field Strength at Center of Triangle

    Homework Statement Three positive charges, A, B and C, of 3 × 10-6, 2 × 10-6, and 3 × 10-6 Coulombs respectively, are located at the corners of an equilateral triangle of side 0.2 meters. Find the magnitude in Newtons/Coulomb of the electric field at the center of the triangle...
  20. W

    Strength of Square Steel Tubing

    Hi I'm a high school student and need help with the calculations for a bike design. I am required for the design to use 1.5" mild steel square tubing at 1/16" thick for it. I need to know what the strength of the tubing is before i can make or tweak the design. Can anyone help with my predicament?
  21. S

    Is permissible stress and tensile strength the same?

    Hi, I am trying to find out if permissible stress and tensile are the same.If not,what is their relation?Thank you.
  22. H

    Oscillator Strength: What Is It & How To Understand It

    Hi.Who can explain to me oscillator strength?
  23. AGNuke

    Strength comparison of Para/Dia-magnetism

    Which one of the following weighs less when weighted in magnetic field? A>SnCl3 B>FeCl3 C>TiCl3 D>VCl3 This is the question I encountered in my Chemistry Olympiad. While I went with B, my institute published answer as A. What I deduced is that A is diamagnetic while the rest are...
  24. M

    Screw and mating thread strength equations

    I am designing a mating male and female threaded interface, where the nut is much weaker than the male thread. I need to be able to calculate a few things: A. The maximum force (as preload) required to reach the yield point of the nut material. B. The torque required to achieve the above. The...
  25. W

    Strength calculations of threaded spindle.

    I have to assess the sizing of a spindle of a DN600 Knife gate valve. The spindle is subjected to two sources of loading acting in both shear and tensile. •Torque applied to the spindle. •Resulting thrust from line pressure. Known data: Required thrust at 2 bar line pressure: F = 53.2 kN...
  26. F

    Calculate Gravitational Field Strength

    Homework Statement Given Radius is 4.76*10^5 m Astronaut drops a hammer of 0.85kg from a height of 1.25m. It takes 3s to reach the ground What is the gravitational field strength? Homework Equations The Attempt at a Solution g=a=Δv/t v=d/t v=1.25/3 a=1.25/3/3 But that's...
  27. J

    Formula for transverse decrease in signal strength?

    Alice is transmitting an electromagnetic beam to Bob. Assume it is a well collimated beam, like a laser beam, or a maser beam. As Bob's distance from Alice increases, his signal strength decreases according to the well known inverse square law. Eve, the eavesdropper, is beside the beam, not...
  28. M

    Mohrs Circle, Von Mises and Minimum Yield Strength Help

    Hi Wasn't sure where to post this, hope it's ok in here! I've gotten myself very confused as to how to find the minimum yield strength for an element. I have used Mohrs circle to find sigma1 and sigma2, then plugged that into the von mises equation to find sigma-von = 636.8MPa. The...
  29. A

    Electric field strength and potential in a charged conducting sphere

    The electric field strength inside a conducting charged sphere is zero, but why? In the book it says "that the field lines would link charges of opposite sign in the sphere and such a state of affairs is impossible under static conditions in a conductor." I don't really get this sentence. And...
  30. H

    Strengthening, crystalline alloys, and yield strength questions?

    Hi, these are questions from my exam from the mechanical behavior of materials. I seriously screwed the exam up. Can you guys help me out? a) Provide two reasons why C is more effective than Ni in strenghtening Fe. b) Explain why single crystalline alloys with fine grains are more...
  31. S

    Comparing Compression strength of chocolates

    Hey there, I am currently working on a project to compare the compression strength of chocolates with different inside filling (caramel, nuts, coconut). I came up with the hypothesis that chocolates filled with nuts would require the most force to break while chocolates with coconut the least...
  32. A

    Youngs modulus vs Ultimate tensile strength

    In case FEA we consider ultimate tensile strength to decide whether component will fail OR pass why ultimate tensile strength is lesser than youngs modulus? Example for copper UTS is 245 MPa n youngs moduls 131000MPa. Why it is like this? Regards, Amlesh
  33. C

    How to determine steel strength formulas

    not sure if I am in the right place or not but nevertheless need some help I am trying to figure the correct steel to use for sign support. I am trying to determine if a 5 x 5 inch with .25 wall is as strong or stronger than a 6 x inch tube with a 3/16 wall. Can't find any formulas to help...
  34. U

    Need help with Gravitational Field Strength question

    Homework Statement A satellite orbites Earth at a distance of 3rEARTH, above Earth's surface. What is the magnitude of gravitational field strength at the point where the satellite is?Homework Equations Fg= Gm1m2/d^2 (m1=mass 1, m2=mass2) F1/F2 = D2^2/D2^2 (D1 is a variable, and so is D2, so...
  35. A

    Gravitational field strength of the earth

    Hi, Using the formula g = \frac{GM}{r2} I found 'g' to equal (9.792121683 x 106 \frac{N}{kg}) The value of g is 9.8 \frac{N}{kg}. I am wondering if I made an error in my calculations or if there is a method of simplifying to get 9.8. Thanks,
  36. P

    Strength of Materials - Steel Beams

    Homework Statement QUESTION 2 (Total 20 marks) Figure 4 below shows a diagrammatic section of the floor of a typical house suspended over a garage. The steel beam shown in section spans 7.2 metres centre to centre of supports. The floor, including an allowance for the self weight of...
  37. N

    Service temperature increases material strength?

    Hello All. I am getting my @$$ kicked by what seems to be a simple concept, and I hope someone can offer me a little help. With some of the nickel based super-alloys such as what are used in turbine blades, why do the alloys get stronger as they get hotter? It seems counter-intuitive to me...
  38. D

    Electromagnet strength independant of number of turns?

    Help me clear up something. I know the magnetic field of an electromagnet's core is given by , where N is the number of turns of wire. Now, the resistance of the wire is given by R = ρ*λ/A, where ρ is the resistivity, and λ the length of the wire. Using Ohm's law to combine them, I get: But...
  39. T

    Using Stress/Strain Curve to Find Yield Strength and Modulus of Elasticity

    Hey guys, I recently did a compression lab with different materials (wood and pvc pipe) and I have to plot the stress/strain curves given the data collected, as well as find yield strength (0.2% offset), ultimate compressive strength, and modulus of elasticity. I've already calculated...
  40. R

    High strength high temp rated non conductive materials

    Does anyone know of any good materials to make pipe out of that can withstand around 200 psig, 250 F and is completely non conductive? Would also be nice if it was durable to external bumps and drops as well. Was thinking carbon fiber but that won't handle high temperature.
  41. M

    Why do different gauss meters measure magnetic field strength differently

    I have used two different Gauss meters to measure the same NdFeB rare Earth N45 (45 MGOe) disc magnet (D28X6mm), with a Residual Induction (Br) of 1320-1380 mT. The first is a Dr. Steingroever GmbH FH51 Gauss meter. It would take readings of up to approximately 1.2 Tesla (12,000 Gauss)...
  42. A

    Resolving Forces to Ensure Motor Strength: A Screw's Tale

    So I have a motor and this motor will turn a screw and bring a platform down to expose fairings during rocket flight. The platform is connected to the fairings. Due to drag pushing the fairings down there will be an upwards force pushing the platform against the screw holding it down. The...
  43. R

    Difference between the acid strength of inorganic and organic acids

    Homework Statement Hi. I'm pretty much a beginner in organic chemistry and I'm just wondering something. For example, I know that HCl is a stronger acid than HF. But... then why the following happens if a have an organic acid (e.g a carboxylic acid)? According to what I see, a...
  44. C

    Strength to Weight & Modulus to Weight

    Homework Statement σ=230MPa (tensile strength) E=15GPa (modulus) ρ=1.85 g/cm^3 (density) Homework Equations Strength/Weight = σ/ρ Modulus/Weight = E/ρ The Attempt at a Solution Strength/Weight = σ/ρ = 230x106 N/m2 / 1850 kg/m2 = 124324.32 (Units?)...
  45. D

    Gravitational field strength for irregular object

    Hi all I'm trying to work out what the surface gravitational field strength of an irregularly shaped body would be (for example Mars' moon Phobos). I know that for a sphere, any point outside it can consider all the mass to be at a point inside it, but for something that's potato shaped, how...
  46. C

    Resultant gravitational field strength

    Homework Statement Consider the objects X and Y, each of mass 8000kg and 2000m apart where XYP forms an equilateral triangle. Determine the resultant gravitational field strength at point P due to objects X and Y. Homework Equations G= GM/R^2 The Attempt at a Solution
  47. M

    What factors contribute to the strength of an atomic interaction or bond?

    hello! which factors determine, which parameters affect, the strength of an atomic interaction or bond? thanks!
  48. S

    How to Calculate Bond Strength in a Molecule?

    √Homework Statement Carbon monoxide molecule, which has a reduced mass of 6.85 amu, absorbs infrared radiation wavelength of 4.6um. if the absorption is due to vibrational transitions, calculate the strength of the bond in molecule Homework Equations u=(m1*m2)/(m1+m2) The Attempt at...
  49. W

    Choosing a Major: Strength or Passion?

    Im on the verge of choosing my major and i have a quick question for everyone. Do you necessarily think that with passion comes strength in a certain field? I am positive that being good at something does not breed a passion for it, but what about vice versa? I recently discovered my...
  50. V

    Wall Strength of a Shipping Container

    I'm going to bolt some hooks to the inside walls of 20ft and 40ft shipping containers. What I'm wondering is, what would be the easiest way to determine the stress on the corrugated steel walls, excerted on it by placing things on these hooks?. The hooks are 280mm apart and the force will be...
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