Box Definition and 1000 Threads

Homework Statement A particle is initially in the nth eigenstate of a box of length 2a. Suddenly the walls of the box are completely removed. Calculate the probability to find that the particle has momentum between p and p + dp. Is energy conserved? Homework Equations solution...

Homework Statement You want to confine an electron and you want to know for certain that the electron's speed is no more than 66 m/s. What is the length of the smallest box in which you can do this? A) 2.8 × 10^-6m B) 1.4 × 10^-6m C) 1.1 × 10^-5m D) 5.5 × 10^-6m Homework Equations...

A disk and a box of equal mass are released from the top of two inclines both of which are a height h above the ground and make an angle θ to the horizontal. Let the radius of the disk be R. How much sooner does the box reach the bottom of the incline than the disk? Express your answer in terms...

Homework Statement A certain force moves a 4-kg box from rest to a velocity of 6 m/s in 3 seconds. If the coefficient of friction between the box and the floor is 0.05, what is the magnitude of the force? Given/Known: mass = 4 kg μ (I'm assuming it means kinetic friction?) = 0.05 time = 3...

Hi, I have to calculate the amount of times a 76g polypropylene lunchbox must be used in order to justify its purchase over disposable 2g polyethylene snaplock bags, in terms of the life cycle energy of the two products. However each time the polypropylene box is used it must be washed using...

*URGENT* Elastic potential energy with box going up an incline. Homework Statement A spring having a force constant of 240 \frac{N}{m} is placed on a plane inclined at 67° to the horizontal. The spring is compressed 0.40 m and a 2.0 kg mass is placed on it. The coefficient of kinetic friction...

Homework Statement Two isolated farms are 12km apart on a straight country road that runs parallel to the main highway 20km away. The power company decides to run a wire from the highway to the junction box, and from there, wired of equal length to two houses. Where should the junction box...

Homework Statement A block slides down a hill. The hill has a gentle 20° slope with respect to the horizontal. The block has an initial speed of 6 m/s. If the block comes to a stop after traveling a total distance of 11 m along the slope, what is the coefficient of kinetic friction between the...

Dear All, Can someone give a specific answer to the question 'What is advantage of using Cast steel over Cast Iron in gear box casings.' Or let me put it like this we have changed our specifcation from CI to CS for Gear Box casing(gear boxes for belt conveyors),now we want revert back due...

Homework Statement So there 2 boxes of nails being lifted at a construction site and one box is 20 kg and the other 10 kg. and the plank tilts towards the heavier box. if the coeficient of static friction is 0.4 draw a FBD for each box of nails and use it to calculate the angle at which...

Does anyone know how to do box notation in Latex, I've got this: Li \quad \boxed{\uparrow \downarrow} \quad \boxed{\uparrow\;} \qquad 1s 2s But I want the quantum states to appear underneath their respective boxes?

Dear All, When an electrical contact is made onto the quantum well, how would the energy states be affected ?

Homework Statement Sam is pulling a box of mass 30kg on a horizontal floor with a force FT= <50N, 30N>. The frictional force acting on the box by the floor is 20N. A) By using Newton's second law find the acceleration of the block. B) What is the normal force acting on the block by the...

Homework Statement An 87-g box is attached to a spring with a force constant of 82 N/m. The spring is compressed 11 cm from the equilibrium position and the system is released. (a) What is the speed of the box when the spring is stretched by 7.0 cm passing the equilibrium? (b) What is the...

Homework Statement What is the maximum possible volume of a rectangular box inscribed in a hemisphere of radius R? Assume that one face of the box lies in the planar base of the hemisphere. NOTE: For this problem, we're not allowed to use Lagrange multipliers, since we technically haven't...

Hello, Say you have a box with two (interacting) particles in them. If you had to venture a guess, what would be most reasonable: that they both have similar velocities, similar momenta or similar kinetic energies? (Or perhaps none of the above?) NB: with "similar" I mean "of comparable...

"Find the most economical dimensions of a closed rectangular box [. . .]" Homework Statement Find the most economical dimensions of a closed rectangular box of volume 8 cubic units if the cost of the material per square unit for (i) the top and bottom is 5, (ii) the front and back is 2 and...

I'm building a simple 20:1 gearbox prototype with 2 compound gears in a row connecting to a third small gear at the end. My goal is to multiply the rotational speed of the small gear. They are all engaged on a straight line. But for some reason they get stuck most of the time. I'm trying to...

Say we have one spin-less electron in a box in the ground state. Say we have dials on the outside of the box that can vary mass and charge of the spin-less electron. Suppose we start with one spin-less electron in a box with m and e set to as near zero as we please, but not zero. As m and e go...

hi all please help me... I'm learning schrodinger equation of a particle in a 1-dimensional box. I read a quantum mechanics book written by A. C Phillips. the wavefuction is ψ (x,t)= N sin (kx) e-iEt/hbar but when I compared to what I read from a modern physics book written by Beisser. the...

Natural Orbitals for "Particles in a Box" Hi, Are Sine waves the natural orbitals for particles in a box when electron-electron interactions are considered? Or is it only true for non-interacting electrons?

Homework Statement What is the degeneracy of the energy level E =65 E0 of the two dimensional particle in a box? Answer Homework Equations E=(h_^2/8mL^2)*(nx^2+ny^2)--> I think we use this eq. The Attempt at a Solution

Incline Surface force deleted

I am trying to make this into jordan canonical form. How can I box in the bottom two lambdas? $$ \left[\begin{array}{ccc} \begin{array}{cccc|} \lambda & 1 & 0 & \\ & \lambda & 1 & 0\\ & & \lambda & 1\\ & & & \lambda\\\hline \end{array} & & \\ & \begin{array}{c|} \lambda\\\hline \end{array}...

Electric Field inside a closed gauss box. Homework Statement there are +2uC and -2uC charges inside a close "Gauss" box. Which of the following statement is true? Homework Equations given option are: 1) the net electric flux through the box is zero 2) the electric field is zero...

Deduce the formula giving the energy levels in terms of n for a free particle in a box of length l, using the fact that only stationary waves can be occupied by the particle. - considering stationary waves, λ = 2l/n. (1) 1) Using E=hv/λ= hvn (2) And P = h/λ, v = h/m*λ, v = hn/2ml (3)...

Homework Statement A 2.00 kg box is moving to the right with a speed of 9.00 m/s, on a horizontal frictionless surface. At t = 0, a horizontal force is applied to the box. The force is directed to the left and has a magnitude F(t) = 6.00 N A) What distance does the box move from its position...

Homework Statement This is problem 13.70 from Beer and Johnston Vector Mechanics 9th ed. A 300-g pellet is released from rest at A and slides with friction along the surface shown. Determine the force exerted on the pellet by the surface (a) just before the pellet reaches B, (b)...

Homework Statement What are the degeneracies of the first four energy levels for a particle in a 3D box with a=b=1.5c? Homework Equations Exxnynz=h2/8m(nx2/a2+ny2/b2+nz2/c2) For 1st level, the above = 3h2/8m For 2nd level, the above = 6h2/8m For 3rd level, the above = 9h2/8m For 4th level...

Let F=(7z+8)i+2zj+(2z+7)k, and let the point P=(abc), where a, b and c are constants. In this problem we will calculate div F in two different ways, first by using the geometric definition and second by using partial derivatives. (a) Consider a (three-dimensional) box with four of its corners...

I think I'm trying to reconcile quantum mechanics and special relativity . . . or whatever I'm doing I'm pretty confused. Ok, so the allowed energy states for a particle in a box are E_n = \frac{\hbar^2 \pi^2}{2 m L^2} n^2 . This seems to mean, as you increase the length L, the particle's...

Box on a sphere is nudged-- when does it fall off? Homework Statement A box of mass "m" is placed on a sphere of radius "r". The box is given an extremely small nudge to get it moving. (a) What is the maximum speed the ball may have without leaving the sphere? (b) At what angle from the...

hello there, i've read in several places the following: if you have a polyene with J double bonds, and taking into account that the average C-C length is aprox 140 pm, then the length of the box is: L=2J*140 And I don't get why 2? the number of bonds is not 2J, but 2J-1, for cases...

Homework Statement A box of mass = 20 kg rests on top of a cart mass = 30 kg. A force of 200 N is applied to the cart, and the box starts to slide. If the coefficient of kinetic friction is 0.25, what is the time it takes for the box to slide 1.5 m. Both the cart and the box start from...

I am attempting to find the angular velocity of a 3D box that is balanced on one of its corners and allowed to fall under the force of gravity alone at the instant the box impacts. Take the simplest case for example where the box is square on all sides and falls in a way that results in one of...

I'm worried about the process of solving this problem, can anyone help me? We are to make a rectangular box, including the top, that has a volume of 144 cubic inches and for which the base is twice as wide as it is deep. The bottom, which must be strong, is made of a material that is three...

Hi Guys, Please see attached diagram. I have done the maths but i am not convinced. Maybe i have missed something but i have not done structural maths for a while. I am using Force = ma where m= mass and a = 9.81m/s2 I need a deflection value for a mass of 19000kg And a mass for...

I'm making a portable generator box, and I'm currently designing the baffles. The design is quite similar to this: http://media.photobucket.com/image/hush%20box/Audiomechanic/ProjectorHushBox1.png There will be an extra wall on the left and right to accommodate louvres on the exterior...

I'm on pg 56 of Thorton's Classical Dynamics book and I see this: Imgur Link Two questions: 1) Where does the 2 go on the second to last equation. 2) Why v0^2 and not v0 on the integral?

Just finished this short film. Sorry for the irrelevance but I'm quite excited and would love some feedback! And I do break the laws of physics in parts ;) https://www.youtube.com/watch?v=XlTGtoevyBk Only 2 minutes and you can stop watching if you get bored! Love to hear your thoughts...

Homework Statement See attachments. Homework Equations The Attempt at a Solution In Example 2.11, why is the work for friction -6(10+Δ)? Why is it negative 6? In Example 2.12, again why is the friction -6, and then where did (Δ-d) come from? I thought Δ is the distance the...

Let A ,B and C represent vectors. we have 1) d/dt (A . B) = A. dB/dt + dA/dt .B 2) d/dt [ A . (BxC) ] = A . (Bx dC/dt) + A . ( dB/dt x C) + dA/dt . (B xC) now the problem in these formulas is that we know that Dot product between two vectors and Scalar triple product of vectors is...

Hi all I need an some help on thermodynamics. I want to install a camera outside of my house, but the camera can only operate between 0 and +55 degrees celsius. Now I want to make an isolating box around it, and wanted to calculate how thick the material of the box should be to allow outside...

Homework Statement A uniform rectangular wood block of mass M, with length b and height a, rests on an incline as shown. The incline and the wood block have a coefficient of static friction, μs. The incline is moved upwards from an angle of zero through an angle θ. At some critical angle the...

Hi, I'm working at a small company currently trying to create a casting mould for double curved surfaces. I'm in charge of programming, and I'm creating a plugin for Rhino which is supposed to take a double curved panel and reorient it to the xy-plane from where it is read and sent to our...

Homework Statement Find the period of small oscillations of a water pogo, which is a stick of mass m in the shape of a box (a rectangular parallelepiped.) The stick has a length L, a width w and a height h and is bobbing up and down in water of density ρ. Assume that the water pogo is...

If you have an image (just black and white) with a box SOMEWHERE in the image, but there's also some noise in the image, is there a good way to find four corners? I'm sure someone has herd of an algorithm for this, it would just be good if I had a direction to go in.

Homework Statement A box with a mass of 22kg is at rest on a ramp inclined at 45 degrees to the horizontal. The coefficient of static friction is 0.78 determine the magnitude of the smallest force that can be applied onto the top of the box, perpendicular to the ramp if the box is to...

Homework Statement Calculate the maximum force required to accelerate the box from rest and not move the glass on it's surface on top of the box. I am given the mass of the box and glass, and both the static and kinetic coefficients of both objects. I have to create a spreadsheet that can...

I want to enclose my final equation inside a box but i find no way to do that in latex. please help me out as soon as possible. Thanks!