Consider a small rigid spherical particle of radius a, fully immersed in a viscous incompressible Newtonian fluid of shear viscosity η above a hard-wall with stick (no-slip) boundary conditions, located at the plane z = 0. A constant positive (external) torque Tx is applied on the particle.
My...
Homework Statement
A concave mirror (f1 = 13.6 cm) and a convex mirror (f2 = −7.00 cm) are facing each other and are separated by a distance of 35.8 cm. An object is placed between the mirrors and is 17.9 cm from each mirror. Consider the light from the object that reflects first from the...
Homework Statement
Homework EquationsThe Attempt at a Solution
I fount these
Part(a)its ##E=\frac {ρa^3} {3ε_0}## and
##υ=\frac 1 2ε_0E^2##
Part (b)
##dU=4πr^2drυ##
Part (c)
##U=\int_0^a 4πr^2udr## but it gives me ##U=\frac {-Q^2} {8πε_0a}##
This"-" bothers me.
Hi,
Calculating the angles in 3D shapes can be a very frustrating and annoying thing. So, I was wondering, are there any mathematical terms, which describe a 3d angles?( "angles" between three lines- part of a sphere)
If there are such terms, suppose a triangular pyramid. Is the sum of those...
I have the following equations:
\left\{ \begin{array}{l}
x = \sin \theta \cos \varphi \\
y = \sin \theta \cos \varphi \\
z = \cos \theta
\end{array} \right.
Assume \vec r = (x,y,z), which is a 1*3 vector. Obviously, x, y, and z are related to each other. Now I want to calculate \frac{{\partial...
Homework Statement
This has been driving me crazy I can't for the life of me figure out how to convert the limits of this integral into spherical coordinates because there is an absolute value in the limits and I'm absolutely clueless as to what to do with with.Homework Equations
$$\int_{\frac...
Homework Statement
A metallic sphere of radius a is placed concentrically with a metallic spherical shell with inner radius b and outer radius c. The sphere has a total charge of 2Q and the shell has a total charge of 3Q.
(a) What is the charge distribution? Specifically, what is...
Hi, I'm no expert in math so I'm struggling with solving these integrals, I believe there's an analytical solution (maybe in http://www.hfa1.physics.msstate.edu/046.pdf).
$$V_{1234}=\int_{x=0}^{\infty}\int_{y=0}^{\infty}d^3\pmb{x}d^3\pmb{y}\...
In one of the lectures I was watching it was stated without proof that the Schwarzschild metric is spherically symmetric. I thought it would be a good exercise in getting acquainted with the machinery of GR to show this for at least one of the vector fields in the algebra. The Schwarzschild...
Hi everyone. I'm looking for a derivation of the Spherical Harmonics that result in the form below given in Sakurai's book. I looked up on web and I found just that these are related with Legendre Polynomials. Has anyone a source, pdf, or similar to indicate me? (I would appreciate a derivation...
Homework Statement
a thick spherical shell carries charge density k/r^2 a<r<b
find E in the three regions r<a a<r<b b<r
Homework Equations
E dot da = Q/ε
The Attempt at a Solution
I can't understand why, when integrating, they choose for
ii to integrate between a and r,
iii and the between a...
<Mentor note: moved from a technical forum and therefore without template>So I´m trying to understand how to use the equation for finding the gradient in spherical coordinates, just going from cartesian to spherical seemed crazy. Now I´m at a point where I want to try out what I have read and I...
Homework Statement
Homework Equations
Gauss
The Attempt at a Solution
I am really confused with question a, I have an idea of how to answer b and c once I obtain an answer for part a... My best guess would be to use Gauss, but I am not sure. Would the field inside be 0? What will the bounds...
Homework Statement
Given ## d \vec r = dr \hat r + r d \theta \hat {\theta} + r \sin \theta d \phi \hat {\phi}.## Find ## d \hat r , d \hat {\theta} , d \hat {\phi}. ##
Homework Equations
I know that ## d \hat {e_j} = \omega^i_j \hat {e_i} ## and that ## \omega_{ij}=- \omega_{ji} ## and ## 0 =...
Homework Statement
A 10-nC point charge is located at the center of a thin spherical shell of radius 8.0 cm carrying -20 nC distributed uniformly over its surface.
What is the magnitude of the electric field 2.0 cm from the point charge?
Homework Equations
E = kq1q2/r^2
The Attempt at a...
Homework Statement
A sphere of radius r_s is at the center of a spherical shell of inner radius r_i=10\, r_s and thickness s = 10\, {\rm cm}\ll r_i.
The sphere has a temperature T_s=1073\, {\rm K} and and an emissivity e=0.90.
The inner surface of the shell has a temperature T_i = 873...
Homework Statement
The angular velocity vector of a rigid object rotating about the z-axis is given by
ω = ω z-hat. At any point in the rotating object, the linear velocity vector is given by v = ω X r, where r is the position vector to that point.
a.) Assuming that ω is constant, evaluate v...
Homework Statement
The problem statement is in the attachment
Homework Equations
E[/B] = -∇φ
∇ = (∂φ/∂r)er
The Attempt at a Solution
I am confused about how to do the derivative apparently because the way I do it gives
E = - (∂[p*r/4πε0r3]/∂r)er = 3*(p*r)/4πε0r4er
Homework Statement
A small spherical rock of mass collides in space with a large spherical rock of mass as indicated in the diagram. After the collision the rocks stick together to form a single spherical object.
https://postimg.org/image/fltmg3bj5/
(New here so I've no clue how to upload...
consider a torus whose equation in terms of spherical coordinates(r,\theta,\phi) is r=2sin\phi for 0\le\phi\le2\Pi. determine the mass of the region bounded by the torus if the density is given by \rho=\phi.
Homework Statement
Here is a copy of the pdf problem set {https://drive.google.com/open?id=0BwiADXXgAYUHOTNrZm16NHlibUU} the problem in question is problem number 1 which asks you to prove the orthonormality of the spherical Harmonics Y_1,1 and Y_2,1.
Homework Equations
Y_1,1 =...
Homework Statement
-here is the problem statement
-here is a bit of their answer
Homework Equations
Chain rule, partial derivative in spherical coord.
The Attempt at a Solution
I tried dragging out the constant and partial derivate with respect to t but still I can't reach their df/dt and...
Situation, a empty universe where there are only concentric spherical shells of mass dm spaced apart by distance dx and contracts under gravity to form a sphere. Assume that there is a point mass in the middle of all the shells. I don't think it would work without it. case1 is an inelastic...
Does anyone know how I could convert data from Planck, which appear as an oval shape, into a form that I can easily map onto a sphere (ie. a rectangular shape in 2:1 aspect ratio)?
Here is an example Planck image: http://sci.esa.int/science-e-media/img/61/Planck_CMB_Mollweide_4k.jpg
I see that...
Hi, I am a physics student and i was asked to answer some questions about Hydrogen atom wavefunctions. I hope you can help me (sorry for my english, is not my motherlanguage, i will try to explain myself properly)
1. In order to find hamiltonian eigenfunctions of Hydrogen atom, we make then be...
The normalized angular wave functions are called spherical harmonics: $$Y^m_l(\theta,\phi)=\epsilon\sqrt{\frac{(2l+1)}{4\pi}\frac{(l-|m|)!}{(l+|m|)!}}e^{im\phi}*P^m_l(cos\theta)$$
How do I obtain this from this(http://www.physics.udel.edu/~msafrono/424-2011/Lecture 17.pdf) (Page 8)?
The...
Homework Statement
What is the gravitational potential both inside and outside a spherical shell of inner radius b and outer radius a?
Homework Equations
φ = ∫g⋅da = -4πGMencl
g = d∅/dr in the r hat direction
The Attempt at a Solution
I can get as far as getting the gravitational field for...
Homework Statement
[/B]
(a) Verify explicitly the invariance of the volume element ##d\omega## of the phase space of a single particle under transformation from the Cartesian coordinates ##(x, y, z, p_x , p_y , p_z)## to the spherical polar coordinates ##(r, θ, φ, p_r , p_θ , p_φ )##.
(b) The...
When do we learn about spherical trigonometry and what are its application(mostly in physics)
I have read a formula named versed sine = 1- cos(θ) in the trigonometry book by S.L loney, I tried it on google to know more about it and the research made me shocked, haversine(half of versed sine)...
Homework Statement
Describe using spherical coordinates the solid E in the first octant that lies above the half-cone z=√(x2+y2) but inside x2+y2+z2=1. Your final answer must be written in set-builder notation.
Homework Equations
ρ = x2+y2+z2
x = ρsinφcosθ
y = ρsinφsinθ
z = ρcosφ
The Attempt...
Homework Statement
Let ##x##, ##y##, and ##z## be the usual cartesian coordinates in ##\mathbb{R}^{3}## and let ##u^{1} = r##, ##u^{2} = \theta## (colatitude), and ##u^{3} = \phi## be spherical coordinates.
Compute the metric tensor components for the spherical coordinates...
Homework Statement
Find the Lagrangian and equations of motion for a spherical pendulum
Homework Equations
L=T-U and Lagrange's Equation
The Attempt at a Solution
[/B]
I found the Lagrangian to be L = 0.5*m*l2(ω2+Ω2sin2(θ)) - mgl*cos(θ) where l is the length of the rod, ω is (theta dot)...
Homework Statement
Suppose the nonconducting sphere of Example 22-4 has a spherical cavity of radius r1 centered at the sphere's center (see the figure). Assuming the charge Q is distributed uniformly in the "shell" (between r = r1 and r = r0), determine the electric field as a function of r...
Homework Statement
In t=0, wave function of the particle that moves freely on the surface of the sphere has the wave function:
Ψ(Φ,θ) = (4+√5 +3√5cos2θ)/(8√2π)
what is time-dependent wave function?Homework Equations
Spherical harmonics
The Attempt at a Solution
I tried normalizing this wave...
Homework Statement
Lets say, there is a non-uniform charge distribution, given as in a spherical shell that has a cavity with radius a and the radius b to the outer surface. I am wondering if the field is discontinuous just on the surface of this sphere.
Homework Equations...
Is there a potential on the inner surface of a charged spherical shell?
I know that there is no electric field on the inner surface, as shown by Gauss's Law, but that isn't enough information to say that the potential (V) there is zero since E = dV/dr, so V could be a nonzero constant.
If...
I know that gravitational potential due to uniform sherical shell at a point outside the shell is equivalent to the potential due to particle of same mass situated at the centre and got proof here http://m.sparknotes.com/physics/gravitation/potential/section3.rhtml. But I was looking for more...
When the inner sphere of a spherical capacitor is grounded and a charge is given to the outer sphere, then it is said that two capacitors are in parallel :
1) outer sphere and the ground and
2) inner sphere and the inner surface of the outer sphere.
My question is about the second one.
Since...
Homework Statement
An electron (S=1/2) is free in a spherical symmetric harmonic potential:
V(r)=\frac{1}{2}kr^2
a) Find energies and degeneracy of ground state and first excited state.
b) For these states find the l^2 and l_z basis.
c) How does these states split in a \vec{L} \cdot \vec{S}...
Hello everyone. In the 3rd edition of Mechanics by Landau and Lifshitz, paragraph 14, there is a problem concerning spherical pendulum. Calculations leading to the integral $$ t=\int \frac {d \Theta} {\sqrt{\frac{2}{ml^2}[E-U_{ef}(\Theta)]}},$$ $$...
Homework Statement
In the figure a nonconducting spherical shell of inner radius a = 2.07 cm and outer radius b = 2.51 cm has (within its thickness) a positive volume charge density ρ = A/r, where A is a constant and r is the distance from the center of the shell. In addition, a small ball of...
Homework Statement
A satellite moving in a highly elliptical orbit is given a retarded force concentrated at its perigee. This is modeled as an impulse I. By considering changes in energy and angular momentum, find the changes in a (semi major axis) and l (semi latus rectum). Show that \delta...
I'd like to expand a 3D scalar function I'm working with, ##f(r,\theta,\phi)##, in an orthogonal spherical 3D basis set. For the angular component I intend to use spherical harmonics, but what should I do for the radial direction?
Close to zero, ##f(r)\propto r##, and above a fuzzy threshold...
I cant't figure out how to transform ##\dot{r}##, ##\dot{\theta}##, ##\dot{\phi}## in spherical coordinates to ##\dot{x}##, ##\dot{y}##, ##\dot{z}## in cartesian coordinates (the dot is Newton's notation for the first time-derivative which is the angular velocity and velocity).
I have no...
Hello everyone I am a new user around here. I have been attempting to understand spherical accretion and create a simple model of that process but I am running into a problem. This is getting at the heart of the issue. So far I have come up with two concentric spheres, the outer sphere is the...
<< Mentor Note -- Thread moved from the technical forums,. so no HH Template is shown >>
Hello! I have a question on Electromagnetics.
Could anyone check if I am on the right track?
Here is the proposed problem:
Consider a spherically symmetric current distribution, which is radial and...
Homework Statement
Let $$\vec H = ih_4^{(1)}(kr)\vec X_{40}(\theta,\phi)\cos(\omega t)$$
where ##h## is Hankel function of the first kind and ##\vec X## the vector spherical harmonic.
a) Find the electric field in the area without charges;
b) Find both fields in a spherical coordinate system...
So I'm reading the Schaum's outlines while trying to prepare for a big test I have in September. And I'm trying to understand something here that maybe someone can offer some clarification and guidance.
So, using Coulomb's Law, we can find the electric field as follows:
\begin{equation}
dE...