Hello, everyone. I have a problem that I solved using Gauss's Law. However, I am unconfident in my answers, as I have very little experience with Gauss's Law.
The surfaces of two large (i.e. infinite) parallel conducting plates have charge densities as follows: \sigma_1 on the top of the top...
this isn't a quack question (is my monitor giving me cancer...etc) but are there any studies involving effects on humans of considerable static electric fields? say low thousands of Vm-1?
what could be possible long/short term effects?
Each quare centimeter of the surface of an infinite p;ane sheet of paper has 2.5 X 10^6 excess electrons. Find the magnitude and direction of the electric field at a point 5 cm from the surface of the sheet, if the sheet is large enough to be treated as an infinite plane.
This is an odd...
Lets say, hypothetically of course, that i know somebody that had something that, with that something being charged, was generating a strong electric field(or maybe electromagnetic waves?) that was emitted in all directions for infinity, if this hypothetical friend were to put a faraday cage...
"Electric fields are not always superposable"
In my Physics textbook by Resnick, Halliday and Krane (Wiley publications), it is mentioned that (pg. 575),
" the principle of superposition of electric fields is not at all obvious and may fail in the case of very strong electric forces."
Can...
I'm completely stumped on three questions, please help...
1. Particle 1 of charge +1x10^-6C and particle 2 of charge -3.0x10^-6C are held at separation L=10.0cm on an x axis. If particle 3 of unknown charge q3 is to be located such that the net electrostatic force on it from particles 1 and 2...
I've been doing some questions and I'm completely stuck on three of them. I tried thinking of how to tackle them but I'm coming up blank.
1. A charge of q is distributed uniformly throughout a spherical volume of radius R. Setting V = 0 at infinity, show the potential at a distance r from the...
emf, current, electric fields...what direction is everything moving?
This is a very simple question but I can't seem to figure out the actual direction that things are moving in a simple circuit. Suppose you have a simple circuit consisting of a battery and a resistor: The electrons inside the...
Consider a uniformly moving charged particle (moving along the x-axis say). Consider an observer a light minute away from the origin, on the y-axis. Now, when the particle crosses the origin, the observer measures that the electric field points towards the origin. Why is this?
This seems...
Electric field lines always point toward:
(_) positive charge
(_) a region of higher potential
(_) ground
(_) a region of lower potential
(X) none of these
Now, i thought that electric fields point towards the negative charge. I submitted my homework, and i missed it. I...
We usually go over stuff after getting the assignments, so I have no clue how to start this question.
Figure 23N-14 shows the deflection-plate system of a conventional TV tube. The length of the plates is 3.2 cm and the electric field between the two plates is 10^6 N/C (vertically up). If the...
Determine the acceleration of a proton (q = +e, m = 1.67 E -27)
in an electric field of intensity 500 N/C. How many times is this acceleration greater then that due of gravity
I'm not so understanding on todays lessons
teh 2 formulas I can recall are f = q*e
and e = f/q
but i don't see...
I need help on a few questions.
1.An alpha particle has a positive charge of 2e and a mass of 6.6 x 10^-27 kg. With what velocity would the particle reach the negative plate of a parallel plate apparatus with a potential difference of 2.0 x 10^3 V.
a)if it started from rest at the positive...
Hi,
I am confused about the electric field within a conductor.
My textbook states that it is zero when charges at rest. Does this mean, the there is no electric field within the metal part of the conductor (let's assume this conductor is a hollow sphere), or the actual "empty" inside core of...
A positive point charge q is placed at x=a and a negative point charge -q is placed at x=-a.
a: find the magnitude of the electric field and the direction at x= 0.
b: derive an expression for the electric field at points on the x-axis. use results to graph the x-component of the electric field...
The period T of an Earth satellite is related to the radius R of its orbit by the equation T^2 = A R^3 where A is a constant. The moon may be assumed to move in a circular orbit of radius RM about earth. The period of the moon's orbit is 28 days. The radius of the orbit of a geostationary...
I have a question that is confusing me perhaps one of you can help me.
If I hook up a constant potential difference to a capacitor and place a dielectric inside of it, will the electric field decrease even if the plate separation remains constant?
I think that the capacitance will increase as...
I'm confused as to how the concept that 'things' have a wavelength applies to an electromagnetic field, which has momentum, but not mass: what 'things' have wavelengths? Are there other criteria, other than whether something has mass or momentum, that must be fufilled before talking about...
I have a general question about dipoles. Doesn't the magnitude of the electric field attain its highest values in the vicinity of the midpoint of the distance between the positive and negative point charges? This is interesting, because if you consider only one point charge, then the magnitude...
A particular Gieger counter has a metal cylinder with an inner diameter of 2 cm along whose axis is stretched a wire with 44 N of tension. The potential difference between the wire and the cylinder is 890 volts. The wire has a length of 6 cm and an outer diameter of 1.5 X 10-4 cm.
A. To find...
Problem: A solid coppper cube is placed in a constant Electric Field in x-direction. The faces of the cube are parallel to xy, yz, xz - plane and one corner is at the origin. Draw the field lines as they would be observed looking down on the cube towards the xy plane. Show at least two...
Here's my problem:
Three 10-cm-long rods form an equilateral triangle. Two of the rods are charged to + 10 nC, the third to -10 nC. What is the electric field strength at the center of the triangle?
Answer in back of book: 1.08 * 10^5 N/C
By looking at the corresponding section, it...
Hi,
Suppose we have a polarized object, and wish to calculate D(r) using
D(r) = epsilon E + P
Do we have to account for the electric field that the polarized object creates, or is it enough to just use the electric field which created the polarization?
Thanks
Ray
I have just read Feynman's QED book and am somewhat perplexed. I have read that photons are the culprit behind all electromagnetic phenomena. He explains electromagnetic radiation very well but I am lost when it comes to static fields. If two electrons are very close together (and repelling each...
Can anybody help me with this problem?
Two small metallic spheres, each with a mass of .20g, are suspended as pendulums by light strings from a common point. They are given the same electric charge, and the two come to equilibrium when each string is at an angle of 5 degrees with the...
Hi; Could somebody please help me with the following question: Dry air will break down and generate a spark if the electric field exceeds about 2.90E+6 N/C. How much charge could be packed onto a green pea (diameter 0.800 cm) before the pea spontaneously discharges?
The formula i used was...
Here's the problem: Can someone help me start it off?
A long straight solenoid of cross-sectional area 6 cm^2 is wound with ten turns of wire per centimeter, and the windings carry a current of 0.25 A. A secondary winding of two turns encircles the solenoid. When the primary circuit is...
I'm having some trouble trying to derive an equation for the movement of a positive ion through a quadropole.
The problem is that my primary source in this is "Physics for Scientists and Engineers with Modern Physics" by Raymond A. Serway and John W. Jewett, Jr. which has an excellent part on...
for the pentagon, there is a + charge at 1, - @2, - @3, + @4, - @5, and + @6. In part A, we are asled to find the net electric field at point P, which is half way between 1 and 2. Each side is 2 mm long, and each charge is an elemental charge. So, I did-
E1=E2=kq/(r^2)...for r I used...
I have a nasty problem here which I have been working at for a while but keep getting rubbish answers.
I have tried using: E = surface charge density/(dielectric constant * Epsilon0 (8.85*10^-12) but I get a dielectric material which has a lower dielectric constant than air.
I really...
Suppose the light bulb in Figure 22.4b is a 60.0-W bulb with a resistance of 240 W. The magnetic field has a magnitude of 0.40 T, and the length of the rod is 0.60 m. The only resistance in the circuit is that due to the bulb. Minimally, how long would the rails on which the moving rod slides...
I'm working on these problems can anyone help me with it?
1. In an EM wave traveling west, the B field oscillates vertically and has a frequency of 56.0 kHz and an rms strangth of 7.90E-9 T. What is the rms strength of the electric field?
2. Pulsed lasers used for science and medicine...
Hi everyone, I just found this forum and am happy I did, being the only physics major in my physics 200 classes (community college :( ), I feel kind of isolated. Groups of people talking about computer science classes, engineering, and I'm alone, and my instructor/advisor still asks me...
1. An electron with a speed of 3.0 x 106 m/s moves into a uniform electric field of 1000 N/C. The field is parallel to the electron's motion. How far does the electron travel before it is brought to rest.
I read the part of the text related to electric fields but I saw nothing that related...
I'm not sure if this has been asked, but i am in major need of help. i have 2 questions. first is determining the speed of a particle when the speed is parallel to the electric field. i talked to my prof. and he suggested finding the energy, U, and by integrating E with respect to z, by doing...
im not sure how to do this...
An electron, starting from rest, is accelerated by a uniform electric field of 8.8×104 N/C that extends over a distance of 7.0 cm. Find the speed of the electron after it leaves the region of uniform electric field.
Hi, I am lazy so I am going to post two questions in the same thread. One of them, I think, has been posted before but I wasn't satisfied with the conclusions in the thread.
1. Suppose that electrical attraction, rather than gravity, were responsible for holding the Moon in orbit around the...
So here's the question:
Two identical small insulating balls are suspended by separate 0.25m threads that are attached to a common point on the ceiling. Each ball has a mass of 8.0 x10^-4kg. Initially the balls are unchaged and hang straight down. They are then given identical positive...
Thank you for taking the time to review my work. I am posting problems with solutions, but I'm not sure if my solutions are correct. The problems are exactly how I have them written in front of me. These are mostly conceptual questions, which require a short answer of some sort.
Q1. A...
I need help understanding electric fields. I basically suck at answering questions related to them (I get 95% of them wrong :cry:).
What I do know about them is:
The electric field vector moves from a positive charge (+q) to a negative charge (-q). (Is this the same case in a capacitor? I...
i have no idea how to do this problem:
a velocity selector consists of electric and magnetic fields described by the expressions E=E(k hat) and B=B(j hat), with B=14.5 mT. Find the vale of E such that a 828-eV electron moving along the positive x-axis is undeflected.
hmm..since it is...
I need some guidance if anyone can help me!
1. A small cube of volume 8.0 cm^3 is .30 cm from a metal sphere that has charge 2.00uC. If the cube is empty, what is the total flux through it?
I tried finding the flux of the sphere as if it was a point charge but I don't know where to go...
1) In the first quadrant (x > 0, y > 0), the x-component of the net electric field is:
always positive.
always negative.
sometimes positive and sometimes negative.
2) In the third quadrant (x < 0, y < 0), the x-component of the net electric field is:
always positive.
always...
Electric fields and electrostatic forces (1 question)
I was wondering if someone can show me how to answer this problem. Thank you.
1)Two charges are placed on the x-axis, an unknown positive charge at x=0 cm and a negative 8.642e-6 C charge at 2.993 cm from the origin. Calculate the...
Hey guys.
Im currently troubled with a physics theory that i can't explain, or prove.
The question:
Discuss whether it would be possible to design a similar train (Magnetic Levitated Train) by putting the electric field to use (and not using a magnetic field at all).
So i have to see...
I am reading a book about general physics kinematics, optics, waves, etc.
It focuses more on history than on explaining equations or sample problems.
One of the sample problems in Electric Fields section asks to find energy and speed when a positron moves from one plate that has electric...
I need help with the following, I don’t even know how to start
A molecule of DNA ( deoxyribonucleic acid) is 2.17μm long. The ends of the molecule become singly ionized – negative on one end, positive on the other. The helical molecule acts as a spring and compresses 1.00 % on becoming...