Strength Definition and 1000 Threads

Hi everyone, I am trying to calculate the decrease in magnetic field strength over distance, using a formula I found on this thread https://www.physicsforums.com/showthread.php?t=522223 The formula given was 1/r^3, where r is the distance from the source. The same thread says the formula...

Homework Statement Use Ampere's Law to show that the magnetic field strength at a distance R from a long, straight wire, carrying a current I, is: H = I/2\piR Homework Equations F=qVB B=\mu0I/2\piR The Attempt at a Solution I'm not sure how to answer this question. I got the...

Homework Statement Two point charges lie on the x-axis. Charge Q1= +7 μC is located at x = 0 and charge Q2 = -18μC is located at x = 25 cm. Find the point on the x-axis (in cm) where the net electric field is zero. Homework Equations E = F/C F = k(q1)(q2)/r^2 The Attempt at a Solution Okay...

Homework Statement We did a lab where we measured the magnetic field strength of a wire coil versus the coil density of the wire coil, keeping current constant. We determined the relationship of B (magnetic field strength) versus n (coil density) to be direct. I need to explain why this is...

Homework Statement How far away from a 360μC charged particle is the electric field strength 49mN/C? Homework Equations E=(8.99x10^{9} x \frac{Q}{r^{2}} The Attempt at a Solution I assumed it would be a simple case of rearranging the equation to give r=\sqrt{\frac{8.99x10^{9}xQ}{E}}...

1. Calculate the forces in the members FG, GD, and CD of the truss shown in the figure by using the principle of virtual work. All horizontal and vertical members are 1m long 2. I have attached the diagram 3. I can easily calculate this using normal principles, but not understanding how to use...

I want to know what factors influence the bond enthalpy of a covalent bond and how do those factors influence the bond strength.

Homework Statement "An electron is accelerated by a potential difference of 1 V and is injected into vacuum. How strong should the magnetic field in a vacuum be if you want the electron to circle along a loop with a radius of 10^-1m? Please indicate the direction of the magnetic field"...

Hey, this was the question could someone please help? "An aluminium single crystal alloy aircraft component is oriented such that a tensile stress is applied along a [102] direction. If slip in this material occurs on a (111) plane and in a [101] direction, compute the yield stress at which...

hi guys! i was wondering if the solid magnet part of a brushed dc motor needs to be strong in order to make a strong motor? I'm designing a motor from scratch and wondering if i should use an existing ferrite magnet that is somewhat strong or should I design a electromagnet that is stronger...

Homework Statement A uniformly charged insulating rod of length 12.0 cm is bent into the shape of a semicircle as shown in the figure below. The rod has a total charge of −7.50 µC. Find the magnitude of the electric field at O, the centre of the semicircle. Homework Equations E = 2kq /...

Homework Statement Three point charges lie along a straight line as shown in the figure below, where q1 = 6.36 µC, q2 = 1.57 µC and q3 = −1.82 µC. The separation distances are d1 = 3.00 cm and d2 = 2.00 cm. Calculate the magnitude and direction of the net electric force on each of the...

Homework Statement Four charged particles are at the corners of a square of side a as shown in the figure below. (Let A = 3, B = 5 and C = 6.) (a) Determine the electric field at the location of charge q. (Use the following as necessary: q, a, and ke.) (b) Determine the total...

Hi, I am interested in making my own (weak) magnets exposing some ferrous metal to the magnetic field of an electromagnet, but this is theoretical rather than something I am able to actually do right now. I am wondering if there are any formulas that can help calculate/estimate the resulting...

Homework Statement In a plate capacitor, the plates has a area of ##100cm^2## and a distance of 3mm. The insulation between the plates is a 1mm glass plate (εr = 10), a 0.5mm thick mica plate (εr = 5) and the rest is air. The insulation layers is parallel with the capacitor plates. The...

Homework Statement The insulation in a plate capacitor consists of two layers with the thickness of 1 and 2 mm, and a relative permittivity of 4 and 6. Calculate the field strength in the thinnest layer when the capacitor is connected to a voltage of 5000v. Homework Equations The...

Hello all, I have to measure the compression strength of a porous ceramic body (d=L=10 mm) using advanced force gauge, mecmesin and don't have any experience with it. The simple procedure, which I followed, was to measure the force at which the sample started to break, divided by the cross...

Homework Statement If the electric field strength between two parallel plates 1cm apart is 3.1kN/C, how much energy will be used by the electric field to move an electron (placed half way between the plates) 3mm nearer to the positively charged plate? Homework Equations Work Done =...

Flywheel? I don't know much about magnets, but if i used magnets on the out side of a flywheel and the inside of the flywheel caseing which repel each other effectively crushing the flywheel to oppose centrifugal forces. Would this creat greater resistance on the rotation of the flywheel? Thanks

Homework Statement A proton enters the gap between a pair of metal plates (an electrostatic separator) that produces a uniform, vertical electric field between them. Ignore the effect of gravity on the proton. a) Assuming that the length of the plates is 11.1cm , and that the proton will...

Homework Statement For parallel electrodes, is the average electric field in the fringe region smaller or larger than in the central region? Homework Equations E = ΔV/ΔX The Attempt at a Solution I know that the electric field strength is proportional to the density of the...

I have a basic question concerning strength and weight of materials. Please forgive me if my question is extraordinarily naive, but I'm an elderly retiree and my education is woefully lacking in this area. Thank you for your patience and understanding. Let us say we have a block of X material...

Two isolated point charges -7μC and +2μC are at a fixed distance apart. At which point is is it possible for the electric field strength to be zero? I don't know where to start with only 2 numbers and no distances. I know that E= kQ/r^2

In my note, we have written the field strength tensor as: F^{\mu\nu} =\partial ^\mu A^\nu -\partial ^\nu A^\mu = \begin{pmatrix} 0&E_x &E_y&E_z \\ -E_x&0 &B_z &-B_y \\ -E_y&-B_z &0 &B_x \\ -E_z&B_y &-B_x&0 \end{pmatrix} But if I look into...

I am just a student. I read that if the strength of weak nuclear force were stronger than current value, this would cause the rarity of neutrons. And, if the strength of weak nuclear force were weaker than current value, this would cause most of hydrogen to convert to helium. I can't understand...

Homework Statement Which law determines the strength of a pull between two objects A. Newtons first law B. Newtons second law C. Newtons law of universal gravitation D. Newtons third law Homework Equations None The Attempt at a Solution I say it is c because a pull is a...

Homework Statement What are the strength and direction of the electric field at the position indicated by the dot in the figure Figure has been attached with the thread Homework Equations E = kq/r^2 The Attempt at a Solution My Complete Solution has been attached to the thread

The question is to rank the inertial forces, euler,coriolis and centrifugal in increasing order of strength, for a observer in the Earth' rotating frame, observing a body stationary in the UK. My thoughts are that coriolis = 2mw X (dr/dt), and so depends on the velocity so can only come into...

A standard way of plotting an S-N (fatigue strength vs no of cycles) graph is to start off by taking a value of Sm (for N=1000) cycles and joining it to the point depicting Se(Endurance Limit). Now we commonly take Sm= 0.9Sut for steels. Now I was wandering, before you actually get to use the...

Homework Statement Hi Can someone please tell me how to set equations for the following problem: A cord of length L is wound on a hollow bobbin (inner radius r and outer radius R). Cord on cord friction (static) coefficient (Ctc) and cord on bobbin (Ctb) friction (static) coefficient...

1.) If a car is in a frontal crash test, and goes hurling into a steel wall for instance, what unit of measure is used to define the strength of the steel wall? For instance, is the resistance strength of the steel measured in tensile strength, yield strength or something else? 2.) Another...

Now I'm sure one can find this at google somehow , even though I wasn't that successful with it. Does someone know what is the highest magnetic field strength for a givem size permanent magnet for example? Like a 1cm ball of neodymium or some other material, what would be the highest field...

Homework Statement A particle with charge q = 4.00 10-6 C and mass m = 1.30 10-4 kg is moving parallel to the Earth's surface at a speed of 1000 m/s. What minimum strength of magnetic field would be required to balance the gravitational force on the particle? Homework Equations Not...

I'm working on a problem but I've hit a road block.. Then the cross section of the piece is here: The first part of the problem is to determine Iy, Iz, and Iyz of the member.. I found the y value of the centroid to be 2.8587" and the z value of the centroid to be 1.0734" using the...

Homework Statement Find the net electric field strength at point A due to the combined electric fields of both charges. Homework Equations E=kq/d^2 The Attempt at a Solution I know how to solve these type of problems however I'm just wondering how come in the net force line as you...

If we could set the strong force to be ten times weaker (compared with the electromagnetic force) how much would the radius of the proton change if any? In the limit that the strength of the strong force goes to zero does the proton radius approach some limit? Thanks for any help!

I have posted a link there to this thread so the OP can view my work.

Hey guys I found this forum and very informative i must say. My question is i found a similar thread but i am wondering. I am building a punching bag frame for 14 punch bags between the weight of 100-120lbs. The span is 23' by 20'. The span of 23' will be broken up with a support in...

The term yield strength is always bugging me deciphering the actual use in some cases. If I had a plate 3m x 2m 30mm material of Yield Strength 355N/mm², does this mean the maximum allowable force at one point on the plate is 10,650N (355 x 30mm), not taking into account safety factors...

Hello, If we have an electromagnet with some lifting force, for example 10N, and make core area smaller at the ends, to concentrate the magnetic field (without saturating the core) according to the formula, for magnetic flux magnetic field density B , will be greater. For example if we...

Homework Statement Steel has a theoretical strength of 4 x 10^10 Pa a density of 7860 kg/m^3, Youngs Modulus of 2 x 10^11 Pa and the mass number of iron, the main ingredient in steel, is 56. Calculate the bond energy of the steel using the expression for theoretical strength and surface...

If I have a magnetic field of say 5 Tesla which is 3m from a concrete wall 0.25m thick how would I go about calculating the strength of the magnetic field on the other side of the wall? Any help/guidance much appreciated!

Hello, Not sure how to go about solving this problem: What outer diameter must a 2mm thick hollow rod have in order to have the same structural bending strength as a solid rod with diameter of 7mm? Also compare the weight per unit length of the two rods. Assume that material is stainless...

Homework Statement Two isolated point charges, -7 μC and +2 μC, are at a fixed distance apart. At which point is it possible for the electric field strength to be zero? (A)......(B)...(C).....(D) o----------------------o----------o---------------o ......-7 μC...+2 μC...

I have 2 magnets , i need to know the force between them , I searched a lot , conclusion was : we need to use a dipole-dipole interaction equation , which included m, which the magnetic dipole , i searched how to calculate it , and this is what i found . m=pl where p is magnetic pole strength...

excedrin migraine is more money but they contain the same exact ingredients. Total sham!

I'm looking to replace a 6x6x12 pressure treated post with 4x4 steel tubing. I was looking at a steel handbook and according to the "design strength in axial compression," a HSS4X4X1/4 for an "effective length" of 12ft is 72 Kips (72,000 lbs). Of course you still need to consider bracing...

Homework Statement By use of the graph in part (a), calculate the gravitational field strength at a distance 2R from the centre of the Earth. Homework Equations g = delta V / Delta r filed strength is the potential gradient The Attempt at a Solution I have drawn the...

Dear Physics Forum, As I understand it, the Higgs field is a quantum field that stretches throughout our universe. Particles that carry mass (for example protons and electrons) acquire this property by interacting with the (local) Higgs field. I assume this interaction can be written in the...

I am working with mild steel 1/16" wall tubing. I am sleeving this over another tube to extend it. The attachment point is 12" past the end of the sleeved tube. How much weight can the extention tube handle before it would bend? Thanks