Homework Statement
Find the pressure on a uniformly charged spherical conducting shell of Radius R and total charge Q. The answer is (Q^2) / (32*π*ε*R^4)
I´m fine doing this using the derivative of the energy as the sphere grows to get the force.
My question is: Why do I get twice the answer...
This problem is driving me mad
suppose that we have a positive charge inside a non conducting spherical shell uniformly charged
the charge is at a random place inside the shell but not in the center
the textbook says the charge will feel no force from the charges of the shell and the...
The volume charge density of spherical shell varies as ρ=-kr.If we have to calculate electric filed using gauss's law, can we treat as E. dA as E(dA) as there is azimuthal symmitry
Homework Equations
The Attempt at a Solution
For example, when a radioactive isotope of Uranium undergoes alpha decay, a radioactive isotope of Thorium is formed. Why isn't this daughter isotope charged?
I am an undergraduate physics student and found myself thinking about a scenario where two positively charged projectiles are fired at an angle to the horizontal at a velocity with a certain separation. So they will be subject to a gravitational force and perpendicular to this, an electrostatic...
hi
i need an equation which can describe the charging time of two parallel capacitors one of them is %50 charged
and if i have a capacitor which is always charged from 50% to 100% and never fully discharged will it have a different impedance than the fully charged/discharged capacitor?
It sounds like an easy-enough problem, but even writing down the ridiculously nonlinear equation that would need to be solved is making my face hurt.
I'm talking classical/Newtonian gravitation, action-at-a-distance, constant-force. It could really be any external non-EM conserved force...
Hey,
I have a series of questions on a basic charged sphere and deriving quantities such as the infinitesimal charge, the total charge and the electric field. The question is part (b) in the image below:
So I found dQ' by equating it to the surface area of a shell at a distance r'...
Homework Statement
The outer conductor (radius b, length l) of a long cylindrical capacitor is earthed. The inner conductor (radius a, length l) is hollow, insulated and uncharged. A sphere of radius R is charged to a potential V far from any other bodies and is inserted inside the inner...
Homework Statement
A soap bubble of radius 0.1mm has a wall thickness of 3.3x10^-8m, and is charged to a potential of 100V. Give a formula for the charge of the bubble.
I know this is probably a really easy question, but I've only ever done problems with spheres of negligible wall...
Homework Statement
The graph in the figure shows the electric field strength (not the field lines) as a function of distance from the center for a pair of concentric uniformly charged spheres. Which of the following situations could the graph plausibly represent? (There may be more than one...
I am new to General Relativity, so this question might sound silly. I know that the source of gravitational field is the stress-energy tensor. What I wonder is how do I find the spacetime metric, gmn caused by a stationary charged particle? What is the stress-energy tensor of a stationary...
Hi, I've been thinking about the concept of charged black holes. What I'm wondering is this; if light cannot escape a black hole, and photons are the bosons of the EM force, then is it meaningful to describe a black hole as having a 'charge'? If the photons can't escape the black hole, then no...
Homework Statement
Ernest Rutherford in his lab at McGill University, Montreal, fired alpha particles of mass 6.64 * 10^-27 kg at gold foil to investigate the nature of the atom. What initial energy must an alpha particle (charge +2e) have to come within 4.7 * 10^-15 m of a gold nucleus...
I have a charged insulating marble -- let's say I used an electrostatic generator to get it up to 1 coulomb, and it weighs 1g (don't make me say 9.8mN). I have it in an insulating "box" whose walls and ceiling are very far away.
I have it sitting still for a long time, so its E field is ~1/r^2...
I know that if you have alternating current in a wire, it will produce electromagnetic waves since the electric and magnetic field change direction continuously as the wave propagates, and that the wave direction, orientation of the E component, and orientation of the B component will all be...
Homework Statement
Identical thin rods of length 2a carry equal charges, +Q, uniformly distributed along their lengths. The rods lie along the x-axis with their centers separated by a distance b > 2a. Find the force, F, exerted by the left rod on the right one.
Left rod's center @ (0,0) → rod...
Black holes only emit hawking radiation which is black body radiation. If black holes only emit photons then the black hole can never get rid of charge which means it can never get rid of all its mass. Does this means black holes also emit charged particles?
Hi all,
I am trying to out what happens when a gravitational wave caused by a monochromatic, electromagnetic plane wave interacts with a charged particle. As we all know, the electromagnetic wave causes the particle to follow a figure of eight shaped path (in the particles rest frame anyway)...
Homework Statement
Homework Equations
DON'T KNOW
The Attempt at a Solution
I can honestly say I've never been this confused by a question. At first my mind automatically went to a=qE/m since I have both charge and mass, but it became apparent that the equation was irrelevant...
Homework Statement
A charged cork ball of mass m is suspended on a light string in the presence of a uniform electric field, as shown in the figure below. When E = (A + B) N/C, where A and B are positive numbers, the ball is in equilibrium at the angle θ.
(a) Find the charge on the ball...
At the end of the derivation, it is given
The electric fiel due to elementary ring at the point P is dE = [2∏rσdrx]/[4∏epsilon zero (x^2 +r^2)^(3/2)
]
To find the total E due to disc is given by
∏σx/4∏ε∫(2rdr)/(x2 + r2)3/2
I am stuck with the calculus done here to arrive at the...
Homework Statement
A solid insulating cone has a uniform charge density of rho and a total charge of Q. The base of teh cone had a radius of R and a height of h. We wish to find the electric force on a point charge of q' at point A, located at the tip of the cone. (Hint: You may use the...
... with constant charge density σ = Q/((pi)a^2)
The Electric field is, after some calculation, is given by E_p below:
z is the z-axis, and a is the radius of the disc.
Now for the questions at the bottom of the page, here are my thoughts:
σ is independent of a because as a->2a, Q->4Q, and...
The Sturm-Liouville Equation describes normal-mode solutions to the general string equation:
\sigma(x)\frac{\partial^2 u}{\partial x^2}=\frac{\partial }{\partial x}\left [ \tau(x)\frac{\partial u}{\partial x} \right ]-v(x)u
Where u(x) is the string's displacement from its equilibrium position...
See attachment.
I don't why a charged particle in a uniform magnetic field will move in a circle. Why can't it just continue straight in the direction its going until another force acts on it?
Homework Statement
Two flat charged plates create a uniform electric field (E). What happens to voltage (V) when the distance (d) is doubled?
Homework Equations
Voltage in uniform electric field:
V = E*d
Capacitance equations:
V = Q/C
C = K * A/d
The Attempt at a Solution...
An electron is accelerated through 2.4 x 105 V from rest and then enters a uniform 1.7 T magnetic field. What are the maximum and minimum values of the magnetic force this particle
experiences?
QV = 0.5mv2
F=QvB
Basically, I've got a final value from the above equations, but I'm not...
Homework Statement
The problem can be found in Jackson's book, I think in chapter 1 problem 3 or something like this.
I must determine the charge distribution of a uniformly charged disk of radius R in spherical coordinates (I've done it in cylindrical coordinates and had no problem). The...
I'm a year 12 physics student and I have a keen interest in the inner workings of a magnet.
I know that magnetic fields are created by the motion of charged bodies.
1. Is this somehow related to the how magnets create their fields, within their structure at an atomic level?
I've heard that...
1. How much work is required to assemble eight identical charged particles, each with
charge q, at the corners of a cube of side a? Explain, based on your answer, whether or
not this configuration is stable.
Homework Statement
A plastic semi-circle/arc with radius R has a non-uniformly distributed charge upon it.
The density of the charge/length is \lambda = \lambda_0 sin\theta
θ is 0 in the middle of the arc
find the electric field in the point where the radius come from
Homework Equations...
Homework Statement
A disk of radius R has a uniform surface charge density σ. Calculate the electric field at a point P that lies along the central perpendicular axis of the disk and a distance x from the center of the disk.
Homework Equations
Electric field due to a continuous...
Say we have one spin-less electron in a box in the ground state. Say we have dials on the outside of the box that can vary mass and charge of the spin-less electron. Suppose we start with one spin-less electron in a box with m and e set to as near zero as we please, but not zero. As m and e go...
Homework Statement
At a particular instant, charge q_1 = 4.80×10^−6 C is at the point (0, 0.250m , 0) and has velocity v_1=(9.2*10^5 m/s) i_hat. Charge q_2 = −2.50×10^−6 C is at the point (0.150m , 0, 0) and has velocity v_2 = (-5.3x10^5 m/s) j_hat.
At this instant, what is the magnetic...
It is known that if a charged particle accelerates then it emits electromagnetic wave (energy). If so then this means that the work we do on particle, W=F*s, doesn't all go to particles kinetic energy, E=0.5*m*v^2. Then this means that Newton's F=m*a doesn't hold for charged objects, particles...
I need help understanding how to calculate various Electric Field Strengths of several point charges (Q) both inside and along two OVERLAPPING identical spheres BUT with on NON-UNIFORM VOLUME CHARGE DENSITIES (-1p non-overlap density on the outside with -4p density overlapping internally) with...
Homework Statement
Two positive charged spheres, with masses m = 2.0 g and with the same charge 2 µC are connected by a rope that is a distance of 5 cm. The charged spheres are at rest and the system is in static equilibrium.
Homework Equations
N/A.
The Attempt at a Solution
The...
It has been stated that a charged particle in the vicinity of a magnetic field experiences a force given by F = qV x B, which states that there is no force when its velocity is zero. It also shows that only the particles direction can be changed, not its kinetic energy.
My question is this...
For my electronics work I have a question to answer:
"A 1000V source is used to fully charge a 1μF capacitor. The capacitor is then disconnected from the source and connected to two additional capacitors (2μF and 8μF) as shown in the circuit schematic below.
a) Calculate the final voltage...
Homework Statement
Suppose we have an outer shell with charge -2Q and radius b. We also have an inner shell with charge Q and radius a. what is the potential when a<r<b.
Homework Equations
E=kQ/r^2
V=kQ/r
E=-dV/dx
The Attempt at a Solution
The method I have been using according...
Homework Statement
A thin charged rod of length L lies along the x-axis as shown in the diagram below.
The charge on the rod is distributed with a density of λ= c x (C /m) where c is a constant.
What is the potential at a point (0,y)? (Your answer should be in terms k, c, L, and y).
See...
My textbook (Halliday & Walker) explains that a charged conductor (a solid, of an arbitrary shape) in electrostatic equilibrium will have the electric field inside be 0 and all electrons will be on its surface. It proves this by saying that if the electric field inside was not 0, the free...
If a charged particle passes through a magnetic field it will be deflected according to the right hand rule, i.e. VxB.
What if the magnetic field lines are parallel to the velocity of the particle? Will the particle still be deflected?
Homework Statement
Graphing The ΔV between three charged metal electrodes, in regards to x distance
Here is the the picture I'm given with the problem. The hint tells me to assume that V=0 when x=0.Homework Equations
C=Q/ΔVThe Attempt at a Solution
I thought the electrodes looked kinda like a...
Homework Statement
Im taking my first physics class and We have to do a research project. The project can be anything we want. I decided to make a c++ program to model a charged particle in a magnetic field. When I first researched the problem I't seemed straight forward enough. The force on a...
Homework Statement
Hi everyone and thank you in advance for your time. I just had this problem on a physics exam (that everyone in the class bombed, and I mean everyone, including the best students). I honestly couldn't care less about the grade, but I really want to understand where I went...
Homework Statement
A Vbatt = 1.5 V battery stores Ubatt = 2.25 kJ of energy. I want to replace this battery with a charged capacitor that stores the same amount of energy and puts out the same voltage. That is, I want a capacitor such that UC = 2.25 kJ and VC = 1.5 V. What must the capacitance...
Homework Statement
The sphere has a radius a and is filled with a charge of uniform. They way I am asked to do this is by building the sphere up layer by layer. And I know that the field outside the sphere is the same as if it were a point charge.
Homework Equations
U = ε/2∫E^2 dv
The...