Spheres Definition and 467 Threads

When a charge is applied to a conducting sphere and connected to another conducting sphere by an ideal thin wire (infinite distance apart), the potential at the surface of each sphere is the same. However, that means (for spheres of different radii) that the charge density on each sphere...

Hi there. I'm new to PF, so please correct me on any mistakes in presenting my question. I'm just hoping to get some direction in doing this problem right. Homework Statement Concentric spherical shells of radius a and b, with b > a, carry charge Q and -Q, repsectively, each charge uniformly...

The figure below shows six concentric conducting spheres, A, B, C, D, E, and F having radii R, 2 R, 4 R, 6 R, 7 R, and 9 R, respectively. Spheres B and C are connected by a conducting wire, as are spheres D and E. Determine the equivalent capacitance of this system. I understand that spheres...

Two uniformly charge spheres are firmly fastened to and electrically insulated from frictionless pucks on an air table. The charge on sphere 2 is three time the charge on sphere 1. Which force diagram correctly shows the magnitude and direction of the electrostatic forces: Explain <...

Was curious how some of you guys would solve this problem... Three conducting spheres of radii a, b and c are connected by negligibly thin conducting wires. Distances between the spheres are much larger than their sizes. The electric field on the surface of a is measured to be E_{a}. What is...

[SOLVED] Charged Aluminum Spheres Homework Statement Two small aluminum spheres, each of mass 0.0250 kilograms, are separated by 80.0 centimeters. How many electrons does each sphere contain? (The atomic mass of aluminum is 26.982 grams per mole, and its atomic number is 13.) Homework...

I'm having difficulty with a problem on MasteringPhysics (such wonderful software...) and as a last resort I'm posting on here. This is, I'm sure, a really simple problem but I'm getting no kind of feedback from MP and there isn't an example problem like this in the book. Homework Statement...

I'm having difficulty with a problem on MasteringPhysics (such wonderful software...) and as a last resort I'm posting on here. This is, I'm sure, a really simple problem but I'm getting no kind of feedback from MP and there isn't an example problem like this in the book. The Problem Two...

Homework Statement Calculate the maximum packing fraction of the unit cell volume that can be filled by hard spheres in the Hexagonal structure Relevant eq: Volume of spheres is number of lattice points multiplied with the maximum volume of one sphere. The Attempt at a Solution I...

Consider two iron spheres, each of diameter 100mm, which are just touching. At what distance r from the center of the Earth will the force of mutual attraction between the contacting spheres be equal to the force exerted by the Earth on one of the spheres? Here's my work... d = distance...

Homework Statement Three spheres, each with a negative charge of 4.0 X 10^6 C, are fixed at the vertices of an equilateral triangle whose sides are 0.20 m long. Calculate the magnitude and direction of the net force on each sphere. Homework Equations Fe = kq1q2 / r^2 The Attempt at...

Homework Statement 9. Two identical conducting spheres, fixed in place attract each other with an electrostatic forces of 0.108 N when their center-to-center separation is 50.0 cm. The spheres are then connected by a thin conducting wire. When the wire is removed, the spheres repel each...

Homework Statement Of the charge Q initially on a tiny sphere, a portion q is to be transferred to a second, nearby sphere. Both spheres can be treated as particles. For what value of q/Q will the electrostatic force between the two spheres be maximized? Homework Equations...

Homework Statement Two spheres, with volume 0.1m^3, and masses M1=200kg and M2=15kg, are connected by a thin wire. They are dropped into the ocean (assume Rho=1000kg/m^3) and allowed to sink Homework Equations The Attempt at a Solution I know buoyancy = Rho * g * V Buoyancy +...

Homework Statement Two small charged spheres (S1 and S2) are suspended from a common point P by cords of equal length l, as shown in the figure below, and make small angles, a1 and a2, with the vertical through P. The charge on S1 is Q and the charge on S2 is 2Q (same polarity). The mass of S1...

Two concentric metal spheres have radii r_1 = 10 cm and r_2 = 10.5 cm. The inner sphere has a charge of Q = 5 nC spread uniformly on its surface, and the outer sphere has charge -Q on its surface. (a) calculate the total energy stored in the electric field inside the spheres Hint: You can treat...

1. 3 conducting spheres of radius a, b, c (a<b<c) are held at a potential of 0, V, 0 respectively. What is the capacitance of the system? 2. Q=CV (which I assume extends to Qi=CijVj for multiple conductors). 3. I've calculated the fields in the two interesting regions, calculated the charge on...

I am trying to correctly understand the following problem: Here is the setup: I have two conducting spherical shells. We will call them S-Left and S-Right. Both spherical shells are initially grounded, therefore, they have no net charge w.r.t. Earth. S-Right is hanging from a string. S-Left...

Homework Statement Two identical conduction spheres are placed with their centers 0.30m apart. One is given a charge of 12 x 10 ^-9 C, the other a charge of -18 x 10 ^-9 C a) Find the electrostatic force exerted on one sphere by the other. b) The spheres are connected by a conducting wire...

Homework Statement A sphere of radius 8.0 cm carries a uniform volume charge density rho = 500*10^-9 C/m^3. What is the electric field at r = 3.0 cm? a.36.0 N/C b.230 N/C c.140 N/C d.565 N/C e.450 N/C Homework Equations E = (k*Q*r)/(R^3), where...

Homework Statement Four 1.0 g spheres are released simultaneously and allowed to move away from each other. What is the speed of each sphere when they are very far apart? The Attempt at a Solution Here's what I got initial potential energy is equal to final kinetic energy. 0.9866...

One of my students Chris wanted to ask this question: are atoms perfect spheres? I could have offered one of my own answers to this but I think he would prefer to hear what you guys have to say. The only thing I would say is that I like the question because of its apparent simplicity. I...

Homework Statement if you guys have trouble reading that, it says, Suppose you make napkin rings by drilling holes with different diameters through two wooden balls (which also have different diameters). You discover that both napkin rings have the same height h, as shown in the figure...

Hi, I am doing a project involving spherical wheels. I need some help with regards to the role played by friction on motion of spheres and cylinders (normal car wheels) on roads. Will friction act forward or backwards ?? Which type of wheel would be more advantageous ? Would appreciate any...

Ive got this one homework problem that i am totally clueless on. Any help? "Two insulating spheres having radii 0.34 cm and 0.54 cm, masses 0.13kg and 0.58 kg, and charges -3x10^-6 C and 2x10^-6 C are released from rest when their centers are separated by 1.2m. How fast is the smaller sphere...

I have heard of such idea: A sphere of fractional dimension 0<s<1 is understood as a probability sphere with probability s to have an electron at a certain position for example the volume of the sphere S^{n-1} in \Re^n has volume Vol(S^{n-1})= (2\Pi^{n/2})/(\Gamma(n/2) and we can...

two spheres are

Hi all, I've got this problem: Consider the points P such that the distance from P to A(-1,5,3) is twice the distance from P to B(6,2,-2). Show that the set of all such points is a sphere, and find its center and radius. I think the setup should be this: sqrt[(x+1)^2 + (y-5)^2 +...

Problem: An insulated spherical conductor of radius r1 carries a charge Q. A second conducting sphere of radius r2 and initially uncharged is then connected to the first by a long conducting wire. After the connection, what can you say about the electric potential of each sphere? How much...

It's been awhile since I've had physics I, so this problem is giving me a headache. Q) Two very small conducting spheres, each of a mass 1.0 \times 10^{-4}\,\,(kg) , are suspended at a common point by very thin nonconducting threads of a length 0.2 \,\,(m) . A charge Q is placed on each...

I have two problems that confuse me for similar reasons. The first one: Find the potential \varphi of an uncharged conducting sphere outside of which a point charge q is located at a distance l from the sphere's center. The second one: A system consists of two concentric conducting spheres...

1)Two small equally charged spheres, each of mass m, are suspended from the same point by silk threads of length l.The distance between the spheres x<<l.Find the rate dq/dt with which the charge leaks off each sphere if their approach velocity varies as v=a/(x)^0.5, a is a constant...

Three identically charged spheres A, B, and C, each with a charge of +3.0 * 10-7 C, are located at the corners of a triangle whose sides are 30 cm long and all the angles are 60 deg. What is the net force acting on sphere A? I figured the X coordinates cancel each other out. For the Y...

Sir, 1) Two spheres of different materials, one with double the radius and 1/4th wall thickness of the other are filled with ice. If the time taken for complete melting of ice in the large sphere is 25 minutes and that in smaller sphere is 16 minutes, what is the ratio of the thermal...

Hi, I have a physics problem I need to solve which I think is quite straight forward but would appreciate some input on whether I'm going down the right lines Tow metal spheres hanging from the roof one of 10g (ball1) and one of 100g (ball2) ball1 is falling from a height of 15cm...

Follow up on the 2 spheres capacitor problem. Help needed before tomorrow! It was probably a bit hard to see what the old topic was about, so I started a new one. I'm still not quite sure on this problem, so I'd REALLY appreciate it if somebody could clear things up a little bit more. The...

The question is the following one: Two isolated conducting spheres of equal radius have charges +Q (#1)and -Q (#2) respectively. If they are separated by a large distance compared to their radius, what is the capacitance of this unusual capacitor? The first remark :wink: : C= \frac{Q}{V}...

The question i am stuck on and am unable to find anything in my notes about (although i can't find my notes from tuesday however we seem to have covered the topic on friday and maybe just not finished it off in time) is ... Two isolated spherical conductors one with radius R and one with...

Two small silver spheres, each with a mass of 12.0 g, are separated by 1.00 m. Calculate the fraction of the electrons in one sphere that must be transferred to the other to produce an attractive force of 3.00e4 N (about 3 tons) between the spheres. (The number of electrons per atom of silver is...

I am studying for my exam for physics and i came across 2 questions that i sort of need help with. 1. Two identical spheres, with charges of Qa=-2Q and Qb=1Q, attract one another with a force of 9.0 x 10^-4 N. A third identical uncharged sphere C touches B and now C is completely removed from...

hi, this is a great forum here and i was wondering if anyone could lend a helping hand , it would be great. im currently studying at univercity for electronics engineering and have been given some physics questions to work onover the holidays. I ahve spend quite some time on this question...

Any help on this question is appreciated. Two small spheres each of mass m are suspended by light strings of light L. A uniform electric field is applied in the x direction. If the spheres have equal and opposite charges of magnitude Q, determine the electric field intensity that enables the...

Hello everyone, I managed to get Parts (a) and (b) of this problem but can't get the last for some reason. A metal sphere of radius 15cm has a net charge of 2.0E-8C. THe question is, at what distance from the sphere's surface has the electric potential decrased by 700V? Well i found the...

the below figure make small angles theta1 and theta2 with the vertical. Figure 21-50 (a) If Q1 = Q, Q2 = 3Q, and m1 = m2 = m, determine the ratio theta1 / theta2. (b) If Q1 = Q, Q2 = 2Q, and m1 = m, and m2 = 4m, determine the ratio of theta 1 / theta 2. I don't get the forces that are...

My question is regarding finding volume and densities of spheres. I'm getting strange results, so I thought I'd find out where my methods are incorrect. I am using a graduated cylinder to drop the spheres into with water inside. I measured the initial volume of the water before I dropped...

In your opinion will we ever use Dyson Spheres? http://www.daviddarling.info/encyclopedia/D/Dysonsp.html In case you don't know what a Dyson spere is.

I have homework, the teacher gave us measuring spheres. He gave us the formula (4/3 π r3) But he didn't show us how to figure out the problem. I don't know how your suppose to figure it out.

Just a couple of questions: 1. If we imagine space to be curved over a sphere is it possible to travel in one direction and eventually end up where you started, assuming that the sphere it self is not expanding. 2. What's the difference between a two sphere and a three sphere? I find it...

In introductory physics laboratories, a typical Cavendish balance for measuring the gravita- tional constant G uses lead spheres of masses 1.8 kg and 13.9 g whose centers are separated by 5.77 cm. Calculate the gravitational force between these spheres, treating each as a point mass...

Howcome the ratio of the surface area of spheres are not equal to the ratio of volume of spheres? For example if I had two spheres, with an aspect ratio of 1:4 when comparing surface areas, yet I have 1:8 between those same spheres when comparing volume. This doesn't make sense to me...