Strength Definition and 1000 Threads

Homework Statement So basically we're given a capacitor, or 2 metal plates, which has the capacity of 400 pikofarads (4*10^-10 F), a voltage of 200 V, and the distance between the two plates is 2 mm (2*10^-3 m). a) Find the charge of a plate. b) The strength of the electric field. c)...

I think this belongs here because its about magnets, except for the adhesive part which may be materials. Im improving my refrigerator door magnets that constantly get knocked off or shift around all the time. 1. What thickness of neodymium magnet will saturate a refrigerator door?? For...

Homework Statement Write an expression for the gravitational field strength E at a point distance r from a planet of mass M. (In my diagram, there are two planets with mass, m and distance 2a apart) Homework Equations The Attempt at a Solution The resultant gravitational field...

Hi all, I've got a pressure vessel that is just an aluminum cylinder with flat caps welded to the ends. Currently, I doing some FEA to properly size those flat caps for a certain factor of safety. Since the pressure in the tank will cause a uniformly distributed load on the wetted surface of...

Homework Statement There is a charge of -4.05mC at (3,0)m and a charge of +3.85mC at (10,0)m. And I have to find the strength and direction of the field at (2.5,7)m. (Direction to be in degrees). Homework Equations E=(kq)/r^2 The Attempt at a Solution I've found the fields to...

Hi all I am looking to measure minute changes in electric field strength. I found this article http://www.physorg.com/news74876394.html" which describes how scientists at harvard isolated a single electron in a highly evacuated, absolute zero chilled chamber and manipulated its movement using...

Homework Statement The bars in the truss each have a cross sectional area of 1.2in^2. If the maximum axial stress in any bar is not to exceed 25ksi, determine the maximum magnitude of P of the loads that can be applied to the truss. Determine the elongation of each member. E=29,000 ksi...

I'v got an interesting querstion to ask. Hopefully someone who's good in the fields of biology will reply. Most people often picture a person as big and bulky when they say he's strong. I always believed that size doesn't have to do anything with strength (take a look at powerlifters)...

Hi, I am trying to work out the electric field strength associated with a number of different electronic systems at a given distance. I am able to simplify the systems so that I only need worry about the fields from a high-voltage busbar or cable. I know that electric field strength from a...

okay guys, i think I am out of my depth on this problem. Im doing a long investigation on eddy currents, and i derived a formula. I am reaching the end of the investigation, and so i wanted to compare my experimental data to expected data. One of the factors i was investigating is the...

I have to spec a sensor to monitor the magnetic field of a DC solenoid element. The specification for the solenoid includes its length, DC resistance, current at the applied supply voltage, and most importantly, the expected Dipole Moment of the unit, as 42 Am^2. I plan to attach a solid...

Hi all, this will be my first physics qns:D more to come... I just learned that value of g at the equator is not exactly equal to the gravitational field strength. Can anyone explain with workings? i don't really understand my teacher workings. Also can i clarify if -We're assuming Earth...

Homework Statement Just wondering if I were to plot the magnetic field strength as a function of time of an RC circuit if they would be related through the time constant in the current (I = Ioe^-t/RC)?

Does anyone have access to a chart shown surface finish vs. impact of fatigue strength at 10^6 for various matals? In our company we limit the surface finishes to 63 Ra max for highly stressed areas. But where did that value come from? The best way to find out is to see a chart showing the...

Say we can set the strength of the strong force weaker, can the glouns then range further and further from a quark? Can we eventually get the strong force to look like the electromagnetic force as far as the range of the force is concerned? Thanks for any help!

I have an "odd" use for pvc pipe. My house is made exclusively of styrofoam and plastic. (and a geodome to boot) I need to stick with this as any other material that was used has failed miserably (wood and steel mainly) my question is, how much weight can a 10' piece of 3" schedule 40...

Sick of watching these documentaries that don't even remotely explain some things in detail. Like... How is bone almost as strong as steel? Some thin steel rods lying around my house are very hard to bend slightly, but my stainless steel scissors in the vice can take a mild hit from a flat...

Hey, I'm 18 (well, in two months) and I have the hypermobility type of Ehlers-Danlos Syndrome (in short, too elastic collagen). Recently, I've started strength- and cardiovascular training to improve my musculature in order to compensate for my weak tissue. Since it's a reasonably rare...

Why does clear tape (used to tape up cardboard boxes) become increasingly harder to tear along the axis that it is stretched? It seems that after a certain amount of deformation, it becomes nearly impossible to tear. This seems to be different then just the restoring force (as opposed to...

What do we mean by different fundamental forces having different relative strength? And if we already consider electromagnetic and weak interaction to be different manifestations of the same force, how are their relative strengths different?

hey guys, i was wondering if there was a formula to measure the strength of a magnet in relation to its size, and what else is needed to be known before such a value can be computed. e.g. its shape, let's say a bar magnet(you have my apology if i have posted in the wrong forum, but I'm...

Homework Statement A + 7.3 nC point charge and a - 2.4 nC point charge are 3.5 cm apart. What is the electric field strength at the midpoint between the two charges? Homework Equations E = 9*10^9(q/r^2) q = charge r = distance from point charge The Attempt at a Solution Since...

3" x3" tube, 3/16' vs 1/8" thick load strength Hello, Any help would be appreciated. After calling umpteen places, and searches, I've found this site, which is a gold mine of info, and thanks for that. I am trying to figure out what the load strength of steel tubing, that is 3" x 3" 3/16"...

What I'm trying to do is compare pipe to channel as far as lateral strength. I have just received a patent, 7,707,794. It's for a building system of walls, fences, and buildings using steel channels and pipe posts. The current way to build a high security fence using expanded metal panels...

Homework Statement Homework Equations State Amperes Law. Show that the magnetic field at a distance R from a very long straight wire carrying a current I has magnitude μ I / (2 pi R) The Attempt at a Solution I really don't know :(

Homework Statement A current I flows to the right on the x-axis from the origin to x = infinity. What's the magnitude of the magnetic field at (x,y) = (0,L)? Homework Equations B = u sub 0 time I/(2 pi R) The Attempt at a Solution We use above equation since we have an extremely...

It's a really tricky one to work out, but does anyone have any suggestions of how to measure compressive strength? Thanks a lot.

I am a teacher and am in the process of developing labs dealing with magnets. I have seen calculators on the internet that can calculate the pull force in pounds for a magnet when provided the shape of magnet, thickness, diameter and Br value in gauss. I have failed to find the equation used...

I know the template needs to be used but i don't want answers i need help starting this. What equation do i use? Here is the question: In a particular region of space, the magnetic and electric fields have energy densities of 0.2 J/m3 and 4 J/m3 , respectively. Calculate the strength...

What quantity has the same numerical value as the gravitational field strength, but is expressed in a different unit? g= 9.8 N/kg i can't think of anything else that's 9.8 besides g

I feel like a stupied girl. :( It think it's not very hard, but I have to have the correct answear before i send it to my school. Homework Statement We sometimes exposed to electric fields. To determine whether there is a risk of flashover is a rule of thumb which states that the sparks will...

What makes something like Potassium nitrate stronger than Sodium Nitrate as an oxidizer?

Hi, This question came up on my midterm and I had no idea how to answer it without redrawing the entire curve as a stress vs. strain curve (which obviously took too long to do). Anyway, I'm just requesting a general procedure, not a numerical answer. If you had a Load (y-axis) vs...

I was assigned a project in Applied Math and I chose to investigate the strength of the relationship between Math and Physics. My scope of tests is still limited, so I decided to first do a chi squared test (to show independence) and then determine the product moment correlation coefficient...

Does anyone know what the relation between frequency and dielectric strength is? I'm mainly concerned with the dielectric strength of air in the High Frequency and Very High Frequency Ranges (3MHz - 300MHz). Thanks.

Homework Statement "A copper cable carrying 50A current has radius 0.003m. What is the electric field if copper has a resistivity of 1.7x10^-8 Ohm/m?" Homework Equations Formula for current density etc. The Attempt at a Solution So I write: \vec{\mathbf{J}} = n|q|v_d = \frac{I}{A}...

Hello guys, Although the response of a motor unit is all-or-none, the strength of the response of the entire muscle is determined by the number of motor units activated. Nerve impulses passing down a single motor neuron will thus trigger contraction in all the muscle fibers at which the...

Hi everyone I just need some help with this question. Its a simple one I'm pretty sure. Homework Statement A solid sphere of radius 3 cm is made from a conductor and has a charge of + 4 uC placed upon it. What is the electric field strength 1 mm from the centre of the sphere? Homework...

I have this equation for the magnetic field strength of an electromagnet but it’s in the form of multiple polynomials. Here is the page where they all are: http://www.netdenizen.com/emagnet/offaxis/solenoidoffaxis.htm since it gives values for e_8 and p_8 I tried using the main equation up...

Hypothetically, say we have X, who's in a relationship with Y. Y is not sure that it's in love with X; which makes X insecure as X is. Or at least, that's what I always see around me. But think about it, wouldn't it be an advantage for X if Y wasn't? I mean, Y acts the way it acts towards Y any...

I have to construct an experiment which measures the electric field strength at various distances from a charged Van Der Graaff generator. How would i go about this?

Hi, I Want to know: High GSM RSSI mean Interference? the reason behind High RSSI ist only Interference? Thanks

Homework Statement 2 masses, 5k and 10kg are fixed in place at the coordinates 1,0 and 1,1 respectively. what combined gravitational field strength do they produce at the point 0,0? Homework Equations g = GM/r^2 The Attempt at a Solution total g = G(5)/(1)^2 +G(5)/2 not the right answer...

1. Estimate the electric field (strength and direction) at the point A. 5cmx5cm gridL 2. E = -dV/ds 3. I had four options, each a combination of 500 or 1000V/m for the E field strength and then left or right for the direction. I knew it must be to the left because the field...

Homework Statement Consider a simple model of a dam. A reservoir of water behind the dam is filled to a height h. Assume that the width of the dam is L. As the reservoir behind a dam is filled with water, the pressure that the water exerts on the dam increases. Eventually, the force on the...

In GR, the strength of gravity goes to infinity at singularities. But what if in nature, gravity increases up to a certain cut-off, and does not continue to increase. If the cut-off is sufficiently low, could it be gravity is not strong enough to overcome pauli exclusion principle, and...

please help?? 1. Homework Statement I got 1/2 of this problem right, but I am not sure of the other part. I have attached the picture. The questions are as follows (with the answers that I am sure of) -- What is the magnetic field strength at point 1 in the figure? What is the magnetic...

Homework Statement I got 1/2 of this problem right, but I am not sure of the other part. I have attached the picture. The questions are as follows (with the answers that I am sure of) -- What is the magnetic field strength at point 1 in the figure? What is the magnetic field direction at...

mobile "lights" I have seen some light making stickers sold that can be put on your mobile and they emit light when you talk. Am I right that they will lower my chances of getting connected when I am far from the antenna? I mean they must somehow make signal weaker, don;t they?

Hi, I have a solution containing acetic acid and NaCl. The solution is adjusted to a particular pH value by adding NaOH. For the calculation of the undissociated acetic acid concentration, I use the correction suggested by Sortwell 2001 (J. Food Prot. 63(2): 222-230 (2000)), which says that...