Forum Definition and 414 Threads

I have to admit I'm a newbie to this forum. My background is computer graphics and physics simulation. I'm not a student but have 20 years of professional experience and an academic background (phd). Here some realtime inteactive physics simulations that may be interesting to you. Could...

Hello everyone, i am new in this forum , me very glad to see all the members of this forum , so please welcome em guys, thanks...

Homework Statement CD is playing for 74 min, starts at angular speed of 480 rpm then slows to 210rpm. what's the magnitude of the angular acceleration Homework Equations angular acceleration =ω/ t The Attempt at a Solution i converted the rev to rad then min to sec then divided...

Long story. Not a homework question, tho sometimes I think the person running the contest would think to use a forum contest to do his coursework. But it's not. Topic: Linear algebra. If no one gets it right after 3 days then we can use any means to get the question right, now becomes a race...

Hi, I am trying to come up with a formula that will generate a price based on its cost. The only trick is that it can't be something constant like 20% or 30% more than the cost. It has to be a formula that adds a bigger profit on smaller numbers and lower profit on bigger numbers. So on a...

Hi people, as you can see i am new in this forum. Sorry if i am posting in wrong section. Im going to try to traduce the problem. " f(n) is the sum o n terms of a arithmetic progression. " Show that : f(n+3) -3f(n+2) + 3f(n+1)-f(n) = 0 I just want to know if -3f(n+2)...

Hi everyone, I'm having some issues understanding how to approach (conceptually) a problem where there is a box with a ramp with static friction. The scenarios that are problematic to me are when you are pushing with a force horizontally and perpendicular to the surface. It's not a...

PForums, I am a writer working on a novel and as part of my job is to research the science behind any idea, I have to make sure is it plausible in real life. I did some research about three years ago for the novel I am writing and got the opinion from scientist and medical experts in regard...

Hi all I use Lyx v1.65 for creating LaTex. Obviously it displays OK in Lyx. It also displays OK with an online editor I've tried http://www.codecogs.com/latex/eqneditor.php But invariably when I try to post LaTex to this forum it does not work. I've tried the sandbox which the reason...

Anyone have suggestion on other forums that are more into antenna theory and design?

I have posted, but people are not wearing enough hats? Hi guys.

does anyone knows a forum specially made for maple so I can get my answers fast? Or will admins of this forums make a special section for maple so people can help each other faster?

Hello, I'm new to this forum, I'm not really sure if this is the correct board to post it on. But I've got a question, I believe regarding exponents and percentages. The problem I've got is that I have a number of 250 different items, and I wanted to know what the odds of randomly selecting...

Dear Fellows If I am on wrong part of forum then sory for that , I need some help regarding VOIDS,,, there are so many work done on voids titled as, PLANE WAVES IN THERMO-ELASTIC SOLID WITH VOIDS, and in abstract they said that , small voids are considered as pores in that solid...

Hi everyone... I found this forum while desperately looking for someone to help me with my statistics assignment, well not just the assignment, just understanding all the new formulas and symbols and things in general. I'm studying psychology and one of my modules is this research statistics...

Dear all, This forum is really great. Iam just wondering if there is any dicussion with regard to Abaqus matters. If there is one, please let me know which section that I should post the message to. For anyone who is not familiar about Abaqus, it is a Finite Element Analysis software that...

Yup, I already have two or three threads in the Academic guidance section, and oddly enough I'm not done yet. I don't want to be an annoying person, so I try not to ask questions upon questions. I'm still hoping to post more, although it wouldn't be a surprise if someone hits me in the face...

Homework Statement It feels good to be back after spending a month in the calculus and beyond section. Here is my question [PLAIN]http://img97.imageshack.us/img97/3883/unleduh.jpg Imagine a spring was pushed back by some distance x_0 and then it ends up at some distance 5m up the ramp...

Hi folks! I am new to this forum and have a question that I hope someone can answer. I have 4 circular holes, 3", 4", 5" and 6". I am covering the holes with 14 gauge sheetmetal. The sheetmetal is circular also and overlaps the holes 1" all the way around. My question is, how many pounds would...

Hi All, New to the forum, but requiring a certain amount of assistance if possible. In relation to ice defrost time, 334 Joules per gram is required to change the state of ice to water and 2.03 joules per gram is required to raise the temperature of ice by one degree? With this in...

Are there supposed to be significant differences in how LaTex is displayed in the Lyx editor and how LaTex is displayed by the processor used by this forum? On this forum, the LaTex expression \int_a^b f(x) dx shows an integral with lower limit a and upper limit b. When I ( as a novice...

Hello how are you all i am new in physics forum Whats up

I am a civil engineer and trying to master a structural analysis program called ETABS which is produced by CSI company. http://www.csiberkeley.com/etabs I am not sure if this forum is a correct place to ask relevant questions. Where do you do recommend to look for tutors and data about...

Hi, Does there exist any form for optical lens design? I am a beginner in this field and would like to find such forum, and have search physicsforums.com, but only found isolated threads without any dedicated subforum. Bob

hello i just sign up to thses forum recommended by a friend to help with mu assignment. i posted a few questions to get help on but no replies. how do i get more replies and help thank you

I have no idea about the topics posted on this part of the forum, nor have I had any slight experience about the things posted. Is this okay or normal if I'm still a first year ME major?

I keep getting great help time and time again. I'm kinda worried people would be sick of me, heh. I think the helpers see that I'm putting a lot of work (I always make sure to scan my answers and write clearly), and thought into the exercise, and I always make sure to thank them. But lately I've...

I've recently started to notice that whenever I reply to some post (even if I'm the first one posting after the OP question), people will often make a later post to the thread seemingly without as much as a glance through mine or other peoples posts in the thread and often repeating what has...

I love entering a question in google and having PF pop up on the first page. Like I did earlier with a "what are the waste products of fusion" and getting the link to: https://www.physicsforums.com/showthread.php?t=121166&page=2 :-p

Hi, Why latex of this forum is horrible? Sometime it does not write what you are writing. Sometime it does not display latex. Sometime, it does not refresh, it will show the same thing even you delete it. etc...

Hello, As part of a research project I'm going to have to run some relatively (for me) advanced stats. Anybody know of a forum where I can post my stats questions? Thanks! Michael

Update: Well, apparently the problem is just that the preview doesn't work on this site. The actual post is fine. Homework Statement I can't use this forum well, because any latex tags I type in are removed. For example, see the tex code below. In the preview (and probably in the real post...

Does anyone know anything about this forum/convention? My kid is interested in bio engineering, and has been invited to attend the forum. She wants to know if this is a good investment of time and money to attend. I think she needs a mentor, but she claims she can't have one through school...

I'm quite new... Everything posted here looks so uni-level. Any high school students?

Hi everyone my name is Erik Ioerger and i just joined your forums. I really appreciate this being on here for i am a high school student and sometimes need help with various topics. Currently my class is covering Periodic Motion, Frequency, and Wavelength questions. Just wanted to thank whoever...

Is there a Math forum as good as this Physics forum? I would like to find it.

How many forums you visit actively (on weekly basis or even monthly basis)? What kind of forums you visit and what's the purpose behind that? How much average time you spend on them? I only visit one and I believe I spend between 15 and 30 minutes per day on average. I started on PF because I...

I did a search on VectorCAST and nothing came up. I am using VectorCAST 5.1h at work, am an amateur user. I need to find a forum that is robust, engaging a large community of users. Thanks in advance... Rhody...

hey guys, I am taking my first electrical engineering class which is circuit analysis. I am having a hard time with it so i was wondering if anybody knew of a website that has tutorials, videos, problems, etc that somewhat follows the course. the material is tough and it seems like theirs not...

What happened to the "Advanced Physics Forum"? I get a DNS error for the url "http://www.advancedphysics.org/". Google doesn't show any news about a shutdown for that site. Anybody know what's going on?

If anyone has ever played the party game, Mafia, you will love this game! This is a kill or be killed, battle of wits, deception and manipulation between an informed minority and an uninformed majority. At the beginning of the game, everyone will be given a role. Some will have actions that...

hello I am a new member in this forum , and I want to learn well with you...sorry I speak little English,so I use google traductor , i speak french , but with french unfortunately there is a little information! now what is a cavity resonant ? and how to write equations for field within...i...

I'm currently learning Mathematica. Are there any forums that you guys usually surf?

The announcement and discussion thread is here. Please also read page 2 of the applicable rules. https://www.physicsforums.com/showthread.php?t=459349

hiya everyone;) I recently found this forum and would hail success for it ..indeed an excellent opportunity for people of all genera to take help from ;) But one complaint... I didn't find a junior here... I mean doing A-Level! If anybody from A-level please reply... I'll be glad! indeed I...

Okay this has been bothering me for a while, why is it that colleges still force Science students to take humanities courses? Didn't we get it over and done with in high school? I have foreign friends who really excel in science subjects, but they are on the verge of nearly failing (like 60%?)...

Hi. When I write my LaTeX code in this forum, it appears completely distorsionated when I click "Preview Changes" in edit mode. For example: n^2(\rho) = n^2_0\left(1-\alpha^2\rho^2)\right) is shown as a "z" if previously I wrote z. In fact, I don't know if this post will be shown well...

I'm trying to make a post, but the latex is frustrating me. I typed in the following two lines. [t*x]KE=\frac{1}{2}mv^2[/t*x] [t*x]=\frac{1}{2}mv\cdot v[/t*x] It just gives me a v and a dot, intead of v dot v, and it put both equations on one line. I attached an image of what showed...

Homework Statement f(x)= lim t-> x [csc(t)-csc(x)]/(t-x). Find the value of f'(PI/4) Homework Equations I can see that this equation somewhat resembles one of the first principle def'ns lim z->x [f(z)-f(x)]/(z-x) The Attempt at a Solution Not really sure how to begin. I...

Homework Statement limx->0+ [tan(\sqrt{x})-sin(\sqrt{x})] / x\sqrt{2x} Homework Equations tanx= sinx/cosx The Attempt at a Solution I set u= \sqrt{x} Therefore as a->0, u->0 And I get the limit =lim x->0+ (tan(\sqrt{x})-sin(\sqrt{x}))/ (x*\sqrt{2}* \sqrt{x}) = 1/\sqrt{2}lim u->0...