Approach Definition and 545 Threads

Homework Statement A charge of -4uC is fixed in place. From a horizontal distance of 55 cm, a particle of mass 0.0025kg and charge -3uC is fired with an initial speed of 15m/s directly towards the fixed charge. How far does the particle travel before it stops and begins to return back...

Homework Statement Two Protons are moving directly toward one another. When they are very far apart, their initial speeds are 2.1 x 10^6 m/s. What is the distance of closest approach? Homework Equations The Attempt at a Solution

Hey folks, I'm not really sure which forum to put this question in but I figured this was probably the best as it deals with issues of regularization. I'm reading Miltons 'The Casimir Effect'. In chapter one he derives the Casimir energy for a massless scalar field by employing...

Homework Statement Distance of Closest Approach Use the similarity between Coulomb's Law and the Law of Universal Gravitation to calculate the distance of closest approach between a point charge of +3.40 × 10-6 C, which starts at infinity with kinetic energy of 8.70 J, and a fixed point...

I'm interested in software development as well as hardware development. A computer engineering program might satisfy my initial needs but my concern is how to properly branch off from there. My desire is to be able to switch seamlessly between the two fields, let's say working for Microsoft on...

Hi everyone. I need to decide which way to go with my education soon. My interest are mainly maths, physics and computers. The thing I could currently see myself work with would be to help create educational software for maths and physics at the level for high school, collage and university...

I am interested in, and try to understand category theory. At the same time, I am taking my first (real) probability class. I am wondering if there is a way to understand probability theory through categories, and more importantly, if so, would it be interesting? It seems that there would...

I would like the perspective of either a physicist or a mathemtician. Please indicate which you are before posting. When learning mathematics, is it better to follow a strictly rigorous approach? By this I mean such things as being exposed to Calculus via Spivak, Complex variables by...

Hi guys, In quantum mechanics, the virial theorem for a system in its ground state is proved by a very nice scaling technique (Nielsen and Martin, PRB, 1985). I was trying to do something similar in classical mechanics and arrived at the virial theorem but i am not sure about why it should...

Am I approach this question right?...finding acceleration Homework Statement A tractor applies a force of 1.3kN to the sled, which has a mass of 1.1x10^4 kg. At that point, the co-efficient of kinetic friction between the sled and the ground has increased to .8. What is the acceleration of...

An extremely elementary question but... Lets say we had a spaceship sitting on Earth under the influence of gravity. Light travels from the ship's floor to the ceiling. An observer 'A' stands near the ceiling. Hence the light loses gravitational potential energy, and therefore decreases...

Proof subset? Given three sets A, B, and C, set X = (A-B) U (B-C) U (C-A) and Y = (A∩B∩C) complement C. Prove that X is subset of Y. Is Y necessarily a subset of X? If yes, prove it. If no, why? ---When I draw the two venn diagrams X and Y, they are the same, but I don't know how to prove...

How do you go about solving an indeterminate beam for various deflections by virtual work? I'm kind of at a loss right now and can't proceed on my homework. I've attached a picture showing the problem I'm confused on - I don't know how to go about modeling the virtual model so I can find the...

As we know, Bondi derives the Lorentz transformations (LT) via the radar detection of the space-time coordinates of a distant event. Once derived from other starting points the LT should account for the results obtained by Bondi expressing them as a function of the Doppler factor...

An analytical approach to the differential equation(urgent) Homework Statement (1) Given the function f: t \mapsto |t|, show that the function f is a differentiable function where t \neq 0 and write f's the differential coffiecient. 2) Given the function g: t \mapsto \sqrt{t^2}, show...

Homework Statement How can I simplify sum from j=0 to infinite of x^(2j) ? Homework Equations The Attempt at a Solution THis is close to the geometric series but I'd have to square each individual term

Homework Statement An infinitely long line of charge has linear charge density 4.00 10-12 C/m. A proton (mass 1.67 10-27 kg, charge +1.60 10-19 C) is 18.0 cm from the line and moving directly toward the line at 1.20 103 m/s. How close does the proton get to the line of charge...

hi I read a few other post about this but I'm an engineer, not a physicist, not a genius and didn't get much wiser. And if it's possible try not to use to many technical terms when you answer this, please. As it says in the title "time slows down when you approach the speed of light", it's...

[SOLVED] trig inequality Homework Statement Use the graph of y = sin x to show the following. Given a triangle ABC, \frac{\sin B + \sin C}{2}\leq \sin \frac{B+C}{2}.Homework Equations The Attempt at a Solution Does anyone else think this question is weird? B < 180 - C so shouldn't their be...

Homework Statement 3. A 15MeV Alpha particle is incident at impact paramter b=0 on a Mg Nucleus, atomic number Z=12 and atomic mass A=24. What is the distance of closest approach? Homework Equations None given, but I thought the following might be relevant: r_{min}=\frac{Zke^{2}}{KE}...

Griffiths develops an intelgral equation for Scrödinger equation in his QM book. As doing so, he requires Green's function for Helmholtz equation (k^2 + \nabla^2) G( \mathbf r) = \delta^3(\mathbf r) A rigourious series of steps, including Fourier transforms and residue integrals follow...

[SOLVED] phasor approach question using phasor approach, determine the current i(t) in a circuit described by the integrodifferential equation: 4i + 8integral(idt) - 3di/dt = 50cos(2t + 75*) the right side is so easy to convert to phasor form, but how can i convert the left side or how to...

I've got to solve this: [x]^13 + 7*[x] + 5 = 0 in ring 91. I've tried solving for [x]^13 and [x] as variables in a Diophante equation but I wasn't able to go anywhere with that. I could try brute force by trying every value for [x] from 0 to 90 but that would just be inconvenient. What...

given the functional integral with 'g' small coupling constant \int \mathcal D [\phi]exp(iS_{0}[\phi]+\int d^{4}x \phi ^{k}) so k >2 then could we use a similar 'Functional determinant approach' to this Feynman integral ?? in the sense that the integral above will be equal to...

OK, I think I have discovered some errors in my thinking about this whole binding energy/release of energy thing. In my other threads, however, you guys often left the subject of my question to explain the next concept (quarks, stellar formations, Q-factors, etc.) The problem was I never...

Hello, I'm familiar with the common calculus approach with partial derivatives to evaluate error propagation in calculations with random variables. However, I'm looking for a way to derive the classic formula with the sum of fractional errors squared: {\left(\frac{\Delta Z}{Z}\right)}^2 =...

Hi all. Could you please recommend some nice books on numerical approach to NLS or introduction to NLS in general? I don't have a strong background in numerical methods nor any prior knowldege in NLS or quantum mechanics. So, perhaps an introductory book would be suitable at this stage. Thanks.

[SIZE="4"]We are doing transient circuit analysis in one of my engineering courses. There are two ways of solving these types of circuits: 1. The step by step approach 2. The differential equation approach. The step by step method is well documented in our textbook, but the differential...

So, I’m wrapping up my junior-ish (looks like I’m on the 4.5 year program) year at UCD majoring in Mech/Aero engineering. I’m starting to think about grad school applications due this November and wanting to get into some research to boost my chances of acceptance. - My question is how do i...

In Rutherford's scattering experiments, alpha particles (charge = +2e) were fired at a gold foil. Consider an alpha particle with an initial kinetic energy K heading directly for the nucleus of a gold atom (charge = +79e). The alpha particle will come to rest when all its initial kinetic energy...

Closest approach of particle problem - Please help! Homework Statement A proton (q = 1e, m = 1u) and an alpha particle (q = +2e, m = 4u) are fired directly toward each other from far away, each with a speed of 0.01c. What is their distance of closest approach, as measured between their...

Solve this equation by superposition approach (undetermined coefficients); pg. 154 in Zill, according to the formula Y = Yc + Yp ---------------------------------------------------- y''' -2y'' -4y' +8y = 6xe^(2x) I got: Yc = C1 e^(-2x) + C2 e^(2x) + C3 xe^(2x) for the complementary...

Is quantum mechanics (QM) local or nonlocal? Different formulations/interpretations (FI) of QM, with or without hidden variables, suggest different answers. Different FI's can be viewed as different algorithms, which leads me to propose an algorithmic definition of locality according to which a...

[SOLVED] A different approach to prime numbers i read something about choosing a finite set of numbers as primes and deriving the other numbers from aforementioned set so that every number is obtained by multiplying primes (the numbers you choose to be prime in your system) in every possible...

In an electromagnetics question I've been asked to calculate the distance of closest approach of an alpha particle which collides with a lead nucleus, but I've never come across the concept of the distance of closest approach. My book is mute on the subject and google yields nothing but more...

lim f(5 + h) − f(5)/h h→0 given that f(5) = 4 and f  (5) = −95. Iam not really sure how to approach this problem. I know its in 0/0 form so you can use L'hosp rules. For another question Iam asked to find the equation for the tangent line of xy 3 + y − 23 = x where y =...

Homework Statement Given a plane S: x+y+z=8 and two points A(6,5,3) and B(10,5,-1), find the point P on plane S such that a line from point A bounces off of the plane S at point P and passes through point B. Homework Equations The Attempt at a Solution If I know that the angle...

For d/dx (cos 4x + sin^(4) x) is it. -sin(4x)(4) + cos^4 (x)? I was unsure on how to approach sin^4. Thanks. Also for d/dx (1)/(16-t^2)^(1/4) Is this correct: (-1/4 (16-t^2)^(-5/4))\((16-t^2)^(1/4))^2?? Thank you.

For the random walk approach to gases, liquids, or solids, why isn't there a gradient? The atoms don't jump by themselves, right? They should have to feel forces to jump...

From "Semiclassical" to Quantum Approach.. If we use the semiclassical expansion of a "path integral" to quantize a theory we have the "Asymptotic series (in \hbar ) I= \int D[\phi]e^{-S[\phi]/\hbar}=I_{WKB}(1+ \sum_{n=1}^{\infty} a(n,X)\hbar ^{n}) The problem is that the "series"...

Hi, I was just wondering what sort of mind-set I should have when approaching Physics as a subject. I personally don't like things to be just in a textbook. I like for things to come alive. I was just wondering how some experts out there approached physics and mathematics...

Not sure which category to post this in (if moderators deem it necessary, then by all means, move it ;))) Anyway, so i read about this new approach from Stephen Hawking so quote time! ;) So what do you think guys? Is it a novel approach or just a retooling of something already existing?

Good evening, I'd like some advice on my approach to learning mathematics (e.g. is this reasonable). Right now I'm interested in computing. I understand basic algorithms such as how quick, heap, merge, insertion and bubble sort work. But that is the extent--I'd love to learn more about...

Hello i didn,t understand the slow motion approach of course i know that: \frac{\partial f }{\partial x^{0}}\sim \epsilon \frac{\partial f }{\partial x^{a}} according to this approach with epsilon<<<1 small parameter for every smooth function my doubts are. a)what would happen to higher...

Time appears to pass more slowly for faster-moving bodies. In other words the faster you travel, the slower time will move for you. When you reach the speed of light time stops. If you travel faster than the speed of light it is assumed you can go back in time. All these natural...

Here is a set of 100-some slides for a talk Daniele Oriti gave in September 2005 called The Group Field Theory Approach to Quantum Gravity http://www.phy.olemiss.edu/GR/qg05/talks/oriti.pdf The talk was given at this conference in Sardinia: http://www.phy.olemiss.edu/GR/qg05/ This is the...

(This is not homework, just part of a curious problem) Is there an analytical (non-numerical) method/way to evaluate \int\limits_0^{2\pi } {\sqrt {1 + \left( {h k\cos kx} \right)^2 } dx} ?

I'm perplexed by semiclassical treatment of Hall effect. I'm referring to Aschroft Mermin text. At page 233 is my doubt: why is it necessary the introduction of w drift velocity vector and why does it take that form? :rolleyes:

Decibel / Intensity Problem, How do I approach it? ASAP.! I have a question, I don't know how to approach it.. I couldn't find a way.. [FONT="Tahoma"]1.Suppose that the sound level of a conversation is Initially at an angry 70 dB and then drops to a soothing 50 dB. Assuming that the...

I have this one problem dealing with Newton's law of cooling: \frac{{dT}}{{dt}} = - k(T - A) I'm basically trying to determine at what time someone died! The info I have is that at time of death, the temperature was 98.6 degrees, at 10 AM it was at 92 degrees, and at 2PM it was at 86 degrees...