Solid Definition and 1000 Threads

Homework Statement In the picture belowHomework Equations Stress=P/AThe Attempt at a Solution I equated stress AB=-stress BC p/pi=-(p-60 kips)/2.25pi P=18.4615kips This is not the right answer according to the book

Homework Statement A long, non conducting, solid cylinder of radius 4.2 cm has a nonuniform volume charge density ρ = Ar^2, a function of the radial distance r from the cylinder axis. A = 2.5 µC/m5. (a) What is the magnitude of the electric field at a radial distance of 3.2 cm from the axis...

Reading about einstein's model of a solid as being made up by quantum harmonic oscillators. Now while the idea is VERY interesting, I think my book's explanation of the multiplicity of an energy state is quite flawed. One can easily derive a simple formula using the binomial coefficient...

Question: A solid sphere of radius R has a non-uniform charge distribution of p=Ar^2, where A is constant. Find total charge Q within the volume of the sphere. p=roe p=Q/dV EdA=qenclosed/Enaught Can you use Gauss' Law for this problem when sphere is solid? If so, how? Since p...

Plasma, the fourth state of matter, is a gas that consists of ions and free electrons. If you cooled plasma would it become a liquid? A solid? What would be the properties of this plasma? would you be able to magnetically separate it?

Homework Statement As the title would lead you to believe I have to classify each solid as a covalent, ionic, metallic, or molecular solid. These are the given solids Calcium Fluoride Rhombic Sulfur Frozen Ethanol Pure Calcium Homework Equations n / a The Attempt at a...

Homework Statement Positive charge is distributed throughout a solid non-conducting cylinder of radius 'b ' and infinite length. The charge density increases with radius according to ρ = {ρ}_{o}({r}{^2}/{b}{^2}), where {ρ}_{o} is a constant (evidently equal to the charge density at the surface...

Homework Statement In my Chemistry lab, we made silver using copper and silver nitrate. We put a solution of silver nitrate, distilled water, and copper wire in a test tube and observed it. Then we took the copper out (the solution turned blue and the copper had crystals formed on it but we...

Use the shell method to find the volume of a solid generated by revolving the region bounded by the given curves and lines about the x-axis. x=2√y x=-2y y=1 So I drew a graph and then using the equation v=∫2πrh and I got the following v=∫(from 0 to 2) 2π(y-1)((2√y)-(-2y)) but...

Homework Statement Hey we have started solids of revolutions using disk, washer, and shell methods. But I came across a problem i cannot figure out. "The region of the graph of y=x^2 and the x-axis, for 0<x<2, rotated about the line y=4. Homework Equations Area of a circle = ∏r^2...

Homework Statement The Attempt at a Solution I dont' see why you don't take the antiderivative of pix^(1/2) which makes it (2pix^(3/2))/3

Homework Statement 2. Determine the concentration of valence electrons in doped (a) Si (a = 0.543 nm) (b) GaAs (a = 0.565 nm) Homework Equations ? The Attempt at a Solution This is the problem, I don't really know what they're looking for. I know what valence electrons are, but...

Hello, Thank you all for the help here. Here we go, I have a known solid weight start of the propellent. I know the PSI of a known volume chamber(After combustion) and Temperature, can I find density? So example Bullseye powder has a load of 0.336954332 grams (5.2 grains) The volume...

I know that particles in a solid are not fixed. They are constantly vibrating about their mean position. That is because of their kinetic energy. I was imagining a situation, lets say solid moves towards left of it's mean position. then the inter-molecular forces of attraction on the left...

Homework Statement A solid conducting sphere carrying charge q has radius a. What is the electric field when r<a. Homework Equations EA=Qenclosed/εo The Attempt at a Solution I found it using gauss law where Q=density*V. I ended up with qr/(4pi*a3*εo)HOWEVER, my friend told me it should be...

Homework Statement Tha band structure of a simple cubic lattice is given by, E = E_{0}-A(\cos k_{x}a+\cos k_{y}a+\cos k_{z}a) where a is the lattice constant and A is a positive constant. Find the effective mass for the electron at the values of k corresponding to the top and bottom...

---------------------------------------------------------------------------- I know about the shell theorem and that the force of gravity due to the mass of the spherical shell is zero inside. I have some questions that may easily be answered for other special cases using the shell theorm and...

I know about the shell theorem and that the force of gravity due to the mass of the shell is zero inside a spherical shell. I have some questions that may easily be answered. 1. Does this same conclusion hold for an ellipsoid and/or a disk with the shell on the exterior rim ? 2. How is...

Hi all Maybe a juvenile question but throw it out there anyways I know India is heavily vested in thorium due to the abudance in that region. I was wondering why current vendors are not looking to develop a thorium burning reactor to market to these guys or at least a modificaion to...

x 0 0.5 1.0 1.5 2.0 2.5 3.0 f(x) 2 1.3 0.9 0.6 0.7 1.1 1.9 Find a formula for the volume V of the solid whose base is the region bounded by y = f(x), the x-axis, and the line x = 3 and its cross-sections perpendicular to the x-axis are semicircles.** So, I...

Homework Statement I uploaded of a picture of the question so hopefully it comes up here. Homework Equations The Attempt at a Solution OK! so i am SO confused on where to start. I am imagining the solid flipped on its side with the x-axis going through its center. So all i...

Homework Statement Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line. y = 5x, y = 5\sqrt{x} about y = 5 Homework Equations A(x)=∏(R2-r2) The Attempt at a Solution A(x)=∏(5x)2-(5\sqrt{x})2) A(x)=∏(25 x2 -...

I'm looking for information about absorption of light per unit (atom, molecule, stoichiometric) in a liquid vs solid. For instance, imagine a unit cube filled with a saturated solution of, say, potassium permanganate, and shine a laser beam through it from bottom to top and measure the...

Homework Statement Question Assuming the torque and maximum shear stress values to be the same for both shafts, determine the size of a suitable soild shaft which could be used instead of the hollow shaft. Information/Data Known Firstly, a previous question - A ship's propellar...

Hello, I am not an electrical engineer but I do have a slight background in some electrical engineering concepts. My question is a general one about relays (more specifically solid state relays but I don't think that really changes my question). I understand that a relay gets a small input...

Homework Statement Solid slab with moment of inertia 2 kg m2 is given the forces as shown. Find the angular acceleration if θ = 37°, R1 = 10 cm, R2 = 25 cm Homework Equations τ = I . α The Attempt at a Solution This is what I've tried although I don't know it is correct or wrong; I tried to...

Hello! I don't understand one easy moment in high temp solid oxydes fuel cells (SOFC): 1. Oxygen ions are moving always via solid electrolite ZrO2? SOFC without load and SOFC in short circuit modes. (High temp is default mean) 2. Electrolises process need electric energy and external...

Homework Statement Find the volume obtained by rotating the solid about the specified line. y=2-(1/2)x, y=0, x=1, x=2, about the x-axis. Homework Equations I used the disk method The Attempt at a Solution I drew a sketch and used disk method. For the radius I used 2-(1/2)x...

Homework Statement Hi, We meet again PF, this time I am little stumped on the following question(link posted down). Homework Equations Link to the question "Question" The Attempt at a SolutionI think I get the gist of it for part (i) my calculated value for equlibirum separation is about...

Homework Statement I've just started with center of mass, and instead of the method in the book, I tried solving the center of mass for a solid hemisphere using angle as a variable, but the answer didn't match. A small disk of mass "dm" is taken, which subtends an angle "dθ" at the center.The...

Hi everyone I'd like to compute the solide angle defined by a cone whose angle θ is known. I tried with the definition but I probably mistook since it lead me to compute an integral worth...0. I then tried with a rule of three, but the result I get is clearly wrong too. Could you...

Homework Statement There is a Ar cube crystal with Lenard jones potential: V^{L.J.}=-\alpha/r^{6}+\beta/r^{12} We know the volume V, the parameters of the L.J. potential, and the mass of the Ar atom (m_{Ar}). Determine the phonon density of state. (D(ω)=?) Homework Equations...

Homework Statement My problem is to calculate the Thermal stress of a Cylindric shell with inner radius a and outer radius b the inner surface is experiencing Temperature T1 and the outer surface is experiencing T2 with T1>T2 assuming that the linear thermal expansion coefficient is a, the...

Hello! I'm trying to derive the formula for the moment of inertia of a solid sphere, and I keep running into a strange solution. I set up the infinitesimally mass of an infinitesimally thin "shell" of the sphere: dm = 4\rho\pir2 dr And then solved for the moment of inertia: I = \intr2dm =...

Say we shoot a bullet that travels in the theta = 0 direction (we are in spherical coordinates). Say the bullet strikes and sticks to a half-infinite isotropic elastic solid that begins at the theta = 90 degrees plane. Is it true that longitudinal waves generated by the bullets impact will be of...

A solid sphere of mass m is released from rest from the rim of a hemispherical cup so that it rolls along the surface. If the rim of the hemisphere is kept horizontal, find the normal force exerted by the cup on the ball when the ball reaches the bottom of the cup.

Homework Statement I've just started with center of mass, and instead of the method in the book, I tried solving the center of mass for a solid hemisphere using angle as a variable, but the answer didn't match. A small disk of mass "dm" is taken, which subtends an angle "dθ" at the center.The...

Find the moment of inertia of a uniform solid sphere of mass,m and radius,a about an axis through its centre. I have tried to solve it but I get the different answer, I don't know where I have done mistake. Please! check and correct my solution below:- Consider a volume element, dv of the...

Might be an easy question (or not). What determines the band gap of an element? As far as I know, silicon is the most efficient single-element semiconductor because of it's small (but nonzero) bandgap. Next (as far as I know) is Selenium. I'm aware there are more efficient compounds, but...

Homework Statement find the volume of the solid bounded by the graphs of the given equations: r=1+cos∅ z=y z=0 (the first octant) Homework Equations V=\int\int rdrd∅ The Attempt at a Solution So, I've been having trouble deciding what to integrate from and to. I...

Question: For c>0, the graphs of y=(c^2)(x^2) and y=c bound a plane region. Revolve this region about the horizontal line y= -(1/c) to form a solid. For what value of c is the volume of this solid a maximal or minimal (Use calculus 1 techniques). First, I found the volume of this...

Can a solid, no matter how small, even a single cell, be evaporated with water vapor from a pool of water?

Homework Statement Hi, thanks for looking! Appreciate it! Right, the question is For a HOLLOW shaft determine, max torque induced, pilot second moment of area, max shear stress at outer edge, and max angle of twist induced in the shaft, with a material modulus of rigidity of 110...

Homework Statement Find the mass of the solid bounded by the cylinder x^2+y^2=2x and the cone z^2=x^2+y^2 if the density is \delta = \sqrt{x^2+y^2} [b2. The attempt at a solution[/b] I had some trouble looking at how to set up the limits on this integral. What I came up with was: 2...

Homework Statement A material has 104 atoms in its primitive cell with a speed of sound of 1500 m/s. It is well above the debye temperature. From Cv=3kb per atom, we calculate the volumetric heat capacity of 1.4*10^6 J m^-3 K^-1. What fraction of he heat capacity is in the acoustic branches...

Homework Statement Sketch the solid whose volume is given by the following integral and then evaluate this integral: ∫(0≤r≤2)∫(0≤θ≤2π)∫(0≤z≤r) (r) dzdθdrThe Attempt at a Solution So, I kind of cheated and evaluated the integral first. So I have ∫(0≤z≤r) (r) dz = rz, from z=0 to z=r, which I...

Homework Statement m=6kg r=0.18m Fapp=33N I'm struggling to understand how to answer this question and correlate the linear force applied to rotation without being given the coefficient of friction causing the rotational motion. The question states that a solid sphere of 6kg is...

Homework Statement An ohmmeter is sometimes used to determine the "direction" of a diode by connecting the ohmmeter to the diode one way and then reversing the ohmmeter leads. If the ohmmeter applies an emf of .5V to the diode in order to determine resistance, what would be the ratio of...

Hi All, I am having issues trying to work out a task my employer has given me and was wondering if there is someone who could help. Question: A Semi-infiniate solid (L=3M) x>0, is initially at temperature zero. At time t=0, a constant temperature Uo>0 is applied and maintained at the face...

I have the working for part d) but I don't understand certain parts, so my problems lie with part d), f) and g) Homework Statement 3. A solid wooden disk is suspended as shown: it has mass 7.70 kg and radius 0.219 m . It is rotated from rest about its vertical axis, reaching an angular...