Radius Definition and 1000 Threads

Here is the question: I have posted a link there to this thread so the OP can view my work.

Hey guys! So I am taking an algebra class at a college but I am still in high school. And I have been really struggling with it. This is one of the problems that has me quite confused: A can in the shape of a right circular cylinder is required to have a volume of 500 cubic centimeters. The...

Homework Statement Copy-paste from my textbook: Let S_1 be the sphere of radius 1, centered at the origin. Let a be a number > 0. If X is a point of the sphere S_1, then aX is a point of the sphere of radius a, because ||aX|| = a||X|| = a. In this manner, we get all points of the sphere of...

Homework Statement Hello. I have this examples about Saturn: A) Calculate the radius of the inner edge of the Cassini division, if you know that this sharp transition in the density of the rings is caused by a 2:1 orbital resonance with the moon ring particles with a moon Mimas, which around...

I have a curved surface which I know the (x,y and z) coordinates for 5 separate points on it and I was wondering how to determine the radius of this curved surface from the coordinates and then interpolate so that I can obtain points across the whole surface? Many thanks.

εHomework Statement A very long solid cylinder of radius R = 6 cm has: -uniform volume charge density ρ = +7 µC/m3. -linear charge density λ = 7.9168E-8 C/m Outside: What is the electric field at a radial distance of 7 cm from the axis of the cylinder? Inside: What is the electric field...

To write the uniform charge density of a disk with radius a in cylindrical coordinates, If we do this form: \rho (x)=\frac{A\delta(z)\Theta (a-\rho)}{\rho} (A is constant that sholud be determined and \theta is step function), we get A=\frac{Q}{2\pi a} and so: \rho (x)=\frac{\frac{Q}{2\pi...

What is the Rate of change of area of circle in respect to radius when radius is 3in I know that that dA/dr is equal to the circumference of the circle But where does that come from? Also the formula for the circumference of the circle is 2(pi)r But the answer is 6 (pi)in^2/in. I understand...

cyclotron -- relationship between velocity and radius in a cyclotron the radius of the path of electron increases.but how if the velocity of the electron is accelerated its kinetic energy should only increase but why is it's radius increasing despite the fact that it's moving to the dee with...

The electric potential immediately outside a charged conducting sphere is 200 V, and 10.0 cm farther from the center of the sphere the potential is 150 V. Determine (a) the radius of the sphere and (b) the charge on it. The electric potential immediately outside another charged conducting sphere...

The solution to this question (whose answer is pi) is eluding me: The radius of a circle is 3 feet. Find the approximate length of an arc of this circle, if the length of the chord of the arc is 3 feet also.

Homework Statement A shock wave moves away from the center of the explosion, its pressure is decreasing, and its speed tends to a constant value. In the filming of a particular explosion, the following data was obtained: t(s): 0, 0.02, 0.04, 0.06 ,0.08, 0.1, 0.12, 0.14, 0.16, 0.18...

I need help getting around this Calculus 3 problem. Any hints will be gladly appreciated: Find the radius of smallest sphere that is tangent to both the lines L1 : x=t+1 y=2t+4 z=−3t+5 L2 : x=4t−12 y=t+5 z=t+17

(2) Find the height of the cone's lateral surface minimum confined to a sphere of RADIUS R. the answer is (2 + sqrt(2)) R

Suppose that I have an atom in one corner of a room, and I fire a photon toward the opposite corner (and assume that it is absorbed there into the wall). There is essentially zero probability that that photon will interact with the atom (either be captured, or stimulate emission, or whatever)...

Does superposition have a radius or a space covered distance which cuts off at a certian point based on the size or coherance of the object. I understand it is a statistical distribution like a blanket of qm possibility as to where the object or particle can collapse. But is there a cut off...

Homework Statement In the figure, sound with a 38.0 cm wavelength travels rightward from a source and through a tube that consists of a straight portion and a semicircle. Part of the sound wave travels through the semicircle and then rejoins the wave that goes directly through the straight...

Hello! I'd like to thank everyone in advance for any help I receive! Homework Statement In January 2006, astronomers reported the discovery of a planet comparable in size to the Earth orbiting another star and having a mass of about 5.5 times the Earth's mass. It is believed to consist...

Homework Statement The speed of a car increases uniformly with time from 50km/hr at A to 100km/hr at B during 10 seconds. The radius of curvature of the bump at A is 40m. if the magnitude of the total acceleration of the car’s mass center is the same at B as at A, compute the radius of...

I am curious how to tell how centripetal accel. changes with radius since there are two equations I can look at a = v2/r or a=wr I read on a thread that if v is constant then use the top equation and if w is constant then use the bottom equation. Is this true? If so, can you please give...

Here is the solution to the problem, all you need to look at is the diagram, the conductivity values and the graph. What I don't get is why the temperature is not continuous when the material changes. Shouldn't there be equilibrium at the boundaries between the different materials?

Newton showed that F=G(m1m2)/r2 When calculating the force of gravity on the surface of the Earth, why do we use the radius of the Earth for our r value? Of course, the above Newtonian equation suggests we should, but it seems rather counter-intuitive. I must admit to not having taken a...

[b]1. "Calculate the radius of a planet with mean density of 3.0x10^3 m2kg-3, from which a golf ball can be thrown to infinity as a velocity of 40 ms-1" Homework Equations I've been looking at the equation of: Vesc=sqroot of 2*G*M/r and rearranging to r=2*G*M/Vesc. However, the...

Homework Statement Visible light passing through a circular hole forms a diffraction disc of radius 0.1mm on a screen. If X-ray is passed through the same set up, what will happen to the radius of diffraction disc? The Attempt at a Solution I'm really clueless regarding this question. I...

I am considering the gravitational time dilation at the centre of a spherical, non-rotating body (such as the Earth). The usual formula for gravitational time dilation is √(1-r_s/r) where r_s is the Schwarzschild Radius and r is the radius of the clock compared to one at infinity, however, this...

Comment, discuss and explain please. Thanka

Homework Statement Estimate the required radius of each plate. The plates are separated in air by 0.01mm and has a capacitance of 400pF. There are 4 pairs of plates. Homework Equations c= εrε0*A(n-1)/ d The Attempt at a Solution Find area. Transposing for A A = dc/εrεo A=...

26. A 2.0-kg block starts from rest on the positive x-axis 3.0 m from the origin and thereafter has an acceleration given by a = (4.0 m/s2)ˆi (3.0 m/s2)ˆj. At the end of 2.0 s its angular momentum about the origin is: A. 0 B. (36kg·m2/s)kˆ C. (+48kg·m2/s)kˆ D. (96kg·m2/s)kˆ E. (+96kg·m2/s)kˆ...

Hello MHB. I am having trouble with the following quesion. Let $R=\{(x,y)\in\mathbb R^2:A\leq x\leq B, C\leq y\leq D\}$ be a rectangle in $\mathbb R^2$ which can be covered (overlapping allowed) with $25$ discs of radius $1$ each. Then $R$ can be covered with $101$ rectangles of radius $1/2$...

Hi, Is it pure coincidence that if you put ##c=v_e=\sqrt{2GM/R}## in the escape velocity, you end up with the Schwarzschild radius ##R=2GM/c^2##? The derivation of the escape velocity is purely classical mechanics. It involves ##E_{kin}=mv^2/2## which is incorrect in special relativity...

Homework Statement Find the radius of convergence and the interval of convergence Homework Equations A_n = Ʃ sum n =1 to infinity [((-1)^n) x^(2n+1)]/(2n+1)! The Attempt at a Solution All I thought was to use the ratio test so I did A_(n+1) /A_n = ((x^(2n+1))/(2n+1)!) (...

Homework Statement I have to find the ratio of RB/RA where R is electrical resistance. Both objects A and B have circular cross section and length L, and are made of the same material. A has radius r0. B has radius r0/2 at the bottom and increases linearly to 2r0. Homework Equations...

For a rotating body, (angular acceleration x radius)= Acceleration of center of mass ? But a rotating body can have angular acc. even if it is not translating. what is wrong?

I know the radiative flux traveling through the atmosphere of a star obeys the equation: dF/dr=-opacity*F*density If we have an isothermal atmosphere the density decreases with radius such that density is proportional to 1/r^2. If the flux entering such an atmosphere from the core of...

Homework Statement I've worked through both parts of this question twice in what I assume is the correct manner, but I'm receiving an unexpected result from part B. The question is as follows: Sand is dumped such that the shape of the sandpile remains a cone with height equal to twice...

find the radius of the small circle O_2:

Homework Statement A small block is standing on top of a big smooth sphere. The small block is initially at rest. The block then glides down the sphere. The block is standing a little to the side for it to move down the sphere but it can be assumed that it is starting at the top. The radius...

One of the most popular mass loss equations of a star, developed by D. Reimers, is given by: dM/dt = -(4x10^-13) * η(L/(gR)) solar masses per year Where η is a free parameter close to unity and L, g, and R are the luminosity of the star, surface gravity of the star, and the radius of the star...

I have a problem: the radius of convergence for the power series \sum(-1)^n \frac{(x-3)^n}{(n+1)} is R=1. Determine the interval of convergence. What does this mean? can anyone help me solve this please

i'm trying to integrate some some function bounded by the x-y domain of x2+y2=6y which is a circle on the x-y plane shifted upward where the outer part of the circle is 6. i'm trying to integrate a double integral.. ∫∫f(x)rdrdθ i don't know how to express my limits of integration for r...

Homework Statement https://scontent-a.xx.fbcdn.net/hphotos-ash3/1390611_10201748262844961_2141774184_n.jpg I need help with 7b. Theorem 3 = termwise differentiation and theorem 4 = termwise integration.Homework Equations The Attempt at a Solution I have no idea how differentiation or...

Homework Statement Estimate (in the order of magnitude) the size of a satellite lens (aperture radius) required to resolve a human face at the surface of the Earth if the satellite is orbiting at an altitude of 100km. Assume λ to be 600nm.Homework Equations θ = 1.22 (λ/D)The Attempt at a...

I've been looking online at multiple resources and seem to be getting conflicting answers. http://www.sciencegeek.net/tables/AtomicRadius.pdf - Where He is slightly smaller than H http://intro.chem.okstate.edu/1314F00/Lecture/Chapter7/ATRADIID.DIR_PICT0003.gif - Where H is smaller than He...

A disc of radius r is spinning about its center in the horizontal plane with a constant angular speed w (omega). A bug walks along the radius of the spinning disc traveling from the center of the disc toward the edge. The bug maintains a constant speed v relative to the disc. (In other words...

Hi, I have a problem which you guys probably could help me solve or at least advise how to approach. I am building a mechanical system that consists of 2 steel rods acting as rails and a platform that travels along. I need to find radius of curvature of a steel rod under stress to see by...

http://puu.sh/4IjIT.png I don't quite understand why this is correct. My initial try was this... (the only difference is at the end, bolded) r = 0.154m period = 0.426s rev per second = 1/0.426s w = 2*pi*(1/0.426) mg = Fn*cosx Fn = mg/cosx Fc = Fn*sinx = mg/cosx = mg*tanx...

Homework Statement Using the Bohr model, find the atomic radius for a singly ionized He+ atom in the n = 1 (ground) state and the n = 2 (first excited) state. Then find the wavelength of the emitted photon when an electron transitions from the n = 2 to the n = 1 state.Homework Equations a_0 =...

there are 2 rings of charge, radius R on the x-axis separated by a distance R, find the potential and E field. so don't you have to calculate the field to the left of the 2 rings, in between the 2 rings and to the right? I get these answers for the E field which by symmetry points only on the...

Homework Statement The area of a label on a cylindrical can is defined by A = 16(pi)x^2 - 68(pi)x + 42(pi). If the height of the can is defined as h = 2x - 7, determine the radius of the can. *Note: the (pi) represents a pi symbol; it would not work on my computer* Homework...