Radial Definition and 481 Threads

Homework Statement A spherical capacitor has internal radius ##a## and external radius ##b##. At time ##t = 0##, the charge of the capacitor is ##Q_0## Then the two shells are connected by a resistor in the radial direction of resistance ##R##. Find the Poynting vector and the energy...

Homework Statement A ball on the end of a string is whirled around in a horizontal circle of radius 0.250m. The plane of the circle is 1.06m above the ground. The string breaks and the ball lands 1.90m (horizontally) away from the point on the ground directly beneath the ball's location when...

Homework Statement For the RDF, we take the square of the radial component multiplied by 4pi r2 (the surface area of a sphere) and this gives us the probability density of finding an electron r distance away. Whats the point in multiplying it by r2? Homework Equations RDF= r2[R(r)]2 The...

I was solving some problems from a textbook and I found this formula for the radial dependence of the sun's magnetic field, ##B(r) \approx B_{\odot} \Big(\frac{R_{\odot}}{r}\Big)^{1/2}##, where ##B_\odot \approx 0.001T## is the magnetic field strength in the photosphere. But how can this formula...

From this link https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations#Measured_observables_of_dark_energy , I can't get this relation : ##c\Delta z = H(z)\Delta \chi\quad\quad(1)## with ##z## redshift, ##H(z)## Hubble constant at redshift = ##z## and ##\chi## radial coordinates. One...

Homework Statement Use a (simplified) graph to compare the maximum probability (electron density) of the Radial Distribution Function for the 1s and 2s orbitals. Homework Equations xxx The Attempt at a Solution The rest I don't how to solve.[/B]

Greetings, I am about to start my master thesis in computational physics and I need to make myself familiar with correlation functions, in particular with the radial distribution function of a system of N identical particles. At Wiki, there is a short explanation of the definition of the...

Hello all, I have been racking my brain with this one all day and I can't seem to figure it out. I have been looking into the forces that would arise from wrapping a string, wire, etc. around your finger. The scenario is illustrated in the attachment. Basically the question is, if we start to...

The potential energy of a particle of mass $m$ is $U(r)= k/r + c/3r^3$ where $k<0$ and $c$ is very small. Find the angular velocity $\omega$ in a circular orbit about this orbit and the angular frequency $\omega'$ of small radial oscillation about this circular orbit. Hence show that a nearly...

Radial and angular nodes are simply a region where the wavefunction is zero. But speaking about their dimensions, do they have any thickness or are they just an infinitesimal point in space without dimensions? Thanks a lot!

I am trying to work out the velocity of the ball in a loop in terms of theta from the horizontal (like a unit circle) as it loses contact with the track. And having a lot of trouble understanding this equation m*g*sin(theta) = m*v2/r and this explanation: The ball will leave the rail when...

Homework Statement I'm not understanding the difference between them, this is for Uniform Circular Motion. Homework Equations ar = -ac = -v2/r The Attempt at a Solution So what i know is radial acceleration goes in a direction towards the radius (perpendicular to velocity), and tangential...

Homework Statement Homework Equations The Attempt at a Solution Can someone tell me where is my mistake ?

My math ability is very limited. How would I determine the input torque required to rotate this radial cylinder arrangement? I started an editable Google Sheet here: https://docs.google.com/spreadsheets/d/1w9VebhPT0S78buN_33hN0ekUggX26lyB4BVugedR1zM/edit?usp=sharing I'm hoping to have a calc...

Okay, so I've been set this homework to find the normalisation constant, N, for the radial wave function in the 2s state for hydrogen (my title was too long to fit that vital information in). thing is; I'm having a bloody hard time and in the process confusing myself with trying to take out all...

And if so, how much? Should the radius be thought of as zero, an infinitesimal, or as the Planck length? v2/r = ω2r If its zero, then you immediately run into a problem when trying to calculate it with linear velocity. v2/r = ar v2/0 = undefined OR ω2r = ar ω20 = 0 Which would mean that...

Homework Statement A 1.75m long PVC pipe with a thermal conductivity of 0.19 W/mK has an internal diameter of 3mm and an external diameter of 5.5mm. Inner temperature is 298K and outer temperature is 273K. Calculate the heat transfer rate through the pipe and thus the decrease in the inner...

Homework Statement A car at the Indianapolis 500 accelerates uniformly from the pit area, going from rest to 320km/h in a semicircular arc with a radius of 200 m. Determine the tangential and radial acceleration of the car when it is halfway through the arc, assuming constant tangential...

Homework Statement Given circuit is a circle, force is a central force[/B] Ueff(r)=U(r)+L^2/2mr^2 Homework Equations the problem i find is, the angular momentum is a function of r however, the solution when differentiate the effective potential, just treat angular momentum as a constant. That's...

Homework Statement Many experiments in physics call for a beam of charged particles. The stability and “optics” of charged-particle beams are influenced by the electric and magnetic forces that the individual charged particles in the beam exert on one another. Consider a beam of positively...

Hi everyone; A very stupid confusion here. When we want to talk about the most probable radius to find the electron in $1s$ orbital, why do we talk about the radial density and not the probability itself? For instance, the probability of finding the the electron at a radial distance $r$...

Dear all, to keep me busy on a Sunday I considered the "1-body radial movement in a (Newtonian) gravitational field problem". I was a bit surprised to find it quite hard finding decent explanations on it. My question is: does anyone have a reference of the explicit solution to the particle's...

15.3.65 Improper integral arise in polar coordinates $\textsf{Improper integral arise in polar coordinates when the radial coordinate r becomes arbitrarily large.}$ $\textsf{Under certain conditions, these integrals are treated in the usual way shown below.}$ \begin{align*}\displaystyle...

When considering bound states of potential energy that tends to zero at large ##r##, my book arrives in $$\frac{d^2}{dr^2} u_{E} = \kappa^2 u \ \ \ \ \kappa^2 \equiv -2mE/ \hbar^2 > 0 \ \ \ \ r \rightarrow \infty$$ from the differential equation satisfied by ##u_{E} \equiv R_{El} (r) / r##...

Hi Guys, I am modelling a simple Magnetic field in ANSOFT Maxwell 15.0. My geometry is a linear array of ring magnets (NdFe30) and spacers (iron) (OD-25mm, ID-13mm). they are arranged in a co-axial fashion and in alternating order (spacer-magnet-spacer-magnet-spacer ect.) and the magnets are...

Does anyone know where I can find information about how to calculate how much extra energy is required of a spaceship to try to thrust perpendicular (or at some angle) to the orbital plane verses flying completely/only in the orbital plane when moving outwards in our solar system? If the...

In uniform circular motion, direction of particle is changing at every moment but its speed remains the same. If the magnitude of velocity or speed remains the same, change in magnitude of velocity is zero. Then how come radial acceleration can have a calculated value since acceleration = change...

Hi! Can anyone tell me what the radial BAO size method is? how do people use it to get to the H(z)? I am reading the paper "Constraints on the Dark Side of the Universe and Observational Hubble Parameter Data " by Zhang et al. and I think I am lost! Can anyone tell me very simple, how they do...

I have an arrangement where a movable pulley has a hook attached. This pulley has to take a load of 5 tonnes and yet move along the horizontal direction. Is it possible to achieve this by using a radial bearing?

I'm a little confused about the proper way to find these null geodesics. From the line element, $$c^2 d{\tau}^2=\left(1-\frac{r_s}{r}\right) c^2 dt^2-\left(1-\frac{r_s}{r}\right)^{-1}dr^2-r^2(d{\theta}^2+\sin^2\theta d\phi^2),$$ I think we can set ##d\tau##, ##d\theta## and ##d\phi## to ##0##...

due to a design issue I'm trying to figur out whether i can get enough thrust to lift a 150-200 kg using some costume made radial fan instead of the usual propellers for a little vtol drone I'm willing to produce. any comment will be much appreciate. Thanks.

I am going through my Quantum textbook, just reviewing the material, i.e. this isn't a homework question. We are solving the radial equation for the Hydrogen Atom, first looking at the asymptotic behavior. My issue is I am completely blanking on how to solve the differential equation...

Homework Statement [/B] Im working through my HNC with the answers but i do not know how they have come to the numbers below.Total load = 1.5/-60 degrees + 2.3/-18 degrees. =(0.75−j1.3)+(2.19−j0.71) 2. Homework Equations . Not sure yetThe Attempt at a Solution I understand how they have...

Voltdrop calculations are made as shown below. Total loadLine currentI=1.5/−60∘⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯+2.3/−18∘⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ =(0.75−j1.3)+(2.19−j0.71) <<< (How to get to these numbers only from above??) =(2.94−j2.01 )=3.56/−34.4∘⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯MVA

Homework Statement 2 A particle P of mass mkg moves on an arc of a circle with centre O and radius a metres. At time t = 0 the particle is at the point A. At time t seconds, angle POA = sin^2 2t. Find (i) the value of t when the transverse component of the acceleration of P is first equal to...

If we consider 2 shells in Schwarzschild spacetime their radial proper distance ##d s^2 = \frac{1}{1-\frac{r_s}{r}}d r^2## follows from the metric with ##dt=0## and ##d\Phi=0##. Integrating yields ##\Delta s## as a function of the r-coordinates of the shells. A reference with the formula for...

Hi all, I'm trying to compute the solutions to a general case for a Schroedinger equation with a radial potential but I'm stuck on a rather small detail that I'm not sure about. It's well known that I can perform the change of variables to spherical coordinates and express the radial part of the...

I know black holes are not that well understood but if someone can explain this I'd be grateful. Please correct me if I have anything wrong, I don't know much about this. The Schwarzschild solution of comes from the Einstein field equation I think I have that right. Now I don't understand...

Hi everyone, To begin, sorry for my english...:S I try to calcualte inner/outer surface stresses on a pipe submitted to instanatenous temperature variation on the OUTER SURFACE. I know the Roark's formua giving the stresses but with an instantaneous temperature variation on the INNER SURFACE...

Homework Statement How do you find the derivative of the radial vector r Homework Equations r [/B]= ru'_r + ru_r r = \frac{dr}{dt}u_r + r\frac{du_r}{dt} can't get latex to work either The Attempt at a Solution [/B] If r is the magnitude of r, how would you find the derivative of it...

Homework Statement The problem asks for the tangential and normal acceleration of the acceleration. We were given that: $$a_x=c*cos[d*t]$$ and $$a_y=c*sin[d*t]$$ where c and d are constants. Homework Equations The book gives us $$a_t=(r\ddot{\theta}+2\dot{r}\dot{\theta})$$, (1)...

Hello can someone explain what is axial and radial moments?

Homework Statement This is a (long) multi-part question working through the various stages of solving the radial Schrodinger equation and as such it would be impractical to type it all out here but I will upload the pdf (https://drive.google.com/open?id=0BwiADXXgAYUHOTNrZm16NHlibUU) of the...

Homework Statement Essentially we are describing the ODE for the radial function in quantum mechanics and in the derivation a substitution of u(r) = rR(r) is made, the problem then asks you to show that {(1/r^2)(d/dr(r^2(dR/dr))) = 1/r(d^(2)u/dr^2) Homework Equations The substitution: u(r) =...

Dear Everyone, Could anyone explain why we count only the number of radial nodes between the subshells that have the same orbital angular momentum l ? For example, 3p-orbitals have 1 radial node that exists between the 3p- and 2p-orbitals. Shouldn't be there additional radial nodes that exist...

Hello, So I was reading wikipedia the other day, as I do from time to time. I came across a rather interesting sample problem posed in the article, but seeing as Wikipedia is horrible in some of their physics articles on explaining what's the hell they're doing, I became lost. Here is the...

Homework Statement By substituting R(r)=r^2*e^(-r/a) into the radial equation for a hydrogenic atom, find the values of a, ℓ and E for which the function R(r).Homework Equations http://puu.sh/rOJQ3/8bcad54c45.png The Attempt at a Solution I took the first derivative of R(r), then multiplied...

Hello! I am just stuck on one part of this question and would be grateful for any help. Question A small block of ice slides from rest from the top of an inverted frictionless bowl of radius R (above right). How far below the top x does the ice lose contact with the bowl? Equations mgx =...

Homework Statement Homework Equations rXF ?? The Attempt at a Solution T= 6 N (r =1) T = 12 N (r=2)

If a force only depends on a radial distance "r" and it only has a radial component in the "er" then is it radially symmetric? This pertains to some homework problem I have, but part of the problem is that I'm not exactly sure what is meant by "radially symmetric". I assume its asking if the...