Thread Definition and 573 Threads

Since the pipe is light , net force and net torque acting on the pipe should be zero . Initially , ##T_A+T_B=3mg## by balancing torques about each end of the rod , we get : $$T_A=\frac{4mg}{3}$$ Let the tension in ##A## just after cutting ##B## be : ##T_A'## Let the normal reactions acting on...

I would like to create a thread to ask a question about plumbing. I have used my cell phone to take photographs of a book about plumbing, and I would like to post these photographs on my thread about plumbing. But when I was in the process of creating a thread, and I posted the photographs on...

Why was the title of this thread anonymously changed in the last couple of days? https://www.physicsforums.com/threads/what-was-schwinger-doing-at-16.1060202/ It was started back in Feb.

Testing testing, one, two, three. Having trouble posting. Seeing if it's that thread or just me.

I was looking through a thread earlier today : I *thought* I had it Watched, but apparently not. and the OP included a graph with data points. Can't seem to find it in Alerts (neither popup, nor my-account alert list), and Searching backwards through recent posts made my eyes glaze over and I...

Any chance the TIL thread will be reopened (or a part 2 started, as has happened with other long threads) ? May one ask what led to its being locked?

To whom it concerns, Would it be possible to reopen the thread "Confusion about scattering in QED". I think I might have some helpful pointers for the OP. If not would it be better to start a new thread? Thanks.

First of all, I don't know where to put this. I had a thread in the advanced physics homework help (https://www.physicsforums.com/threads/calculating-the-transfer-function-for-dark-matter-numerically.1052335/#post-6883072) but it just vanished overnight. I never got a notification or something...

I know, I know, yet another Twin Paradox thread. (My apologies if this is already on the Forum somewhere. I found a similar discussion but with no answer to my question. I'd appreciate a link if someone has already given an answer to it.) I'm trying to construct the time elapsed for Stan...

In looking at a thread that was rejected because, well, it was rubbish, it reminded me of a famous sketch: If you haven't seen it before, enjoy it. Thanks Bill

A thread where we chat about car maintenance. What maintenance are you doing lately? What cost did you pay? What are things you've been recommended by your servicer that you're undecided on doing? Here is one for me: "engine system cleaning" ($200) The tech said it's recommended...

Hello All, I know there are rules of thumb and thread engagement calculators online but I am trying to find mathematically what the minimum number of threads acceptable would be. I currently have an eyebolt that will be torqued to a specific value. This eyebolt setup will then need to lift a...

I've read the NIRCam instrument uses HgCdTe imaging sensors... "JWST NIRCam has ten 2K × 2K HgCdTe detectors" https://jwst-docs.stsci.edu/jwst-near-infrared-camera/nircam-instrumentation/nircam-detector-overview I found this chart which displays the relative sensitivity of the NIRCam sensor...

This thread shall be a place where we can talk about anything fast-food related. Does anyone here actually dislike fast food? I know it's not healthy, but it's sure darn good. ...The Mexican pizza is back at Taco Bell. I like certain items at Taco Bell, but this is not one of them. I...

This is a "super thread" designed to encourage chat on anything assets-related: stocks bonds real estate commodities precious metals fine art/collectibles (including, NFTs) cryptocurrency & alternative assets...etc. As someone who is years away from being able to own a home, I would love to...

The thread: https://www.physicsforums.com/threads/question-about-a-stronger-relativity-paradox-than-the-twin-paradox.1009978/ proposed an interesting SR scenario. The thread could have led to instructive discussion of exactly how relativity of simultaneity resolved a "false paradox" that...

From a letter to the Editor in NYT recently: "We are addicted to fossil fuels, de-forestation and over population. Addressing global warming via technology...is like asking a bartender to help with alcoholism" So...mods, need to move it to the correct thread section ?

I am a student at high school who just finished a paper about nuclear energy and I really learned a lot from it. I found the topic interesting and really enjoyed learning about it. I now am searching out more people who know about it and as much information as I can fins while having good...

Trying to discern how to measure/record infiltration of noise into my yard/home. The thread referenced is v2k. Author of thread was trying to build a v2k unit, I believe. What type of engineer is needed to record/prove continual intrusion and what equipment is needed? Would appreciate some...

I need advice how to calculate thread pull out in aluminium 6063-T6. 12 bolts screwed into an aluminium plate (thread depth 25 mm) must withstand a load of 350 kg. Thanks in advance

I'm reading Brian Greene's latest book 'Until the End of Time' (I'll pause here while you finish groaning at yet another layperson reading popularist physics books.) In it, he's describing entropy in a way I've never heard before and it clarifies something that's always stuck on my craw about...

At first I tried solving the problemteh following way: Due to symmetry let the rods connected to the green rod have tension forces in magnitde T1 => mg = 2T1cos(a), where a is half the angle formed by the two rods. From tere I got an expression from the longer rods in the force projected by them...

Hi guys see below thread (duplicated by mistake). Many Thanks

I have the following code public class Assignment1 { public static void main(String[] args) { int x= Integer.parseInt(args[0]); int y= Integer.parseInt(args[1]); int z= Integer.parseInt(args[2]); if (x<0 || y<0 || z<0) {...

I hope it is ok for me to borrow this post: No HW help required here. I just wanted to have LaTeX enabled forum to post my answer to this thread in r/calculus Work: If $$y= \left( \int_0^x (t^{3}+1)^{10}\, dt\right) ^3 $$ then $$\begin{gathered} \tfrac{dy}{dx} =3 \left( \int_0^x...

OK, so I was reading thru a prior thread UNLEARNING THE BLOCK UNIVERSE, initiated by user Lynch101, and which has already been locked by the forum. There were many good responses. It was stated that PRESENTISM and the BLOCK UNIVERSE are 2 philosophical interpretations of the very same LTs, and...

I would like to duplicate the Physics Forums thread posting machinery on my own site so 5 colleagues and I can have our own very small group discussions. Someone offered html syntax which had a box with a button, but the button didn't do anything and I did not know how to get the button to...

Hi, I'm not sure if it's a good idea to start a thread about the following problem but I didn't want to PM anyone. Some time ago I came across a thread which had stats related to the problems faced by students learning the theory of relativity. It showed like how many undergraduates really...

WARNING! This thread contains spoilers for Star Wars: The Rise of Skywalker. If you have not yet seen the movie, we strongly encourage you to turn around and return once you have. Please use this thread for discussions about The Last Jedi, including spoilers. :smile:

Imagine a massless (or very light-weight) charge that is glued to a rod undergoing sinusoidal motion along an axis. The acceleration of this charge produces electromagnetic waves, which can be harvested for energy, and this energy can be used to power the continued sinusoidal motion as well as...

a) Describe the motion of the spool: it will roll down the plane, rotating counter clockwise. I am confused when setting up equation of torque. If I take center of the spool as pivot, only the tension of thread produces torque but the direction will be clockwise and it makes the spool will move...

This question has a naturally associated question which is how common is life? Not just on Earth but anywhere in the universe. To begin making assumptions of the likelihood of life outside of our planet we have to first understand how life arose here first. Since we have not found any evidence...

I have a C++ program that starts two threads from the parent thread, I need to kill both children from a child thread. ____> b | a - |_____> c I need to kill b & c from b. Issue is, I can't use simple flags, as c waits for input using cin. Any help appreciated.

here delete, thread, and const are obviously keywords, I saw this when the system libraries threw a breakpoint, not my code, I'm new at this and that line of code makes very little sense to me, afaik, (const thread&) should be a conversion operator, how can you set an operator to a statement...

My first thread was closed for being too confusing to read. I will try to make it more clear. Also some more parameters: Rod and solid has 0 restitution, solid is anchored and does not move, it is instantly deleted upon collision.

Homework Statement A tiny, 0.60g ball carries a charge of magnitude 8.0 mircoC. It is suspended by a vertical thread in a downard 300 N/C electric field. What is the tension in the thread if the charge on the ball is (a) positive, (b) negative? Homework Equations E=F/q or E=mg/q When i use...

I thought there would already be a thread for this by now, but there isn't so here we go! Post REU offers/acceptances and such here to help each other out :) Here's my list: Texas A&M Cyclotron - Accepted 2/22 Duke TUNL (first round offers scheduled to be sent out 2/25) UChicago for Women &...

Homework Statement The torsion balance shown in the figure consists of a 40 cm long bar with lead balls with a diameter of 2 cm on each end. The rod is hanging by a 100 cm long silver thread with a diameter of 0.5 mm. When two bigger lead balls (density = 11.4 g/cm3) with a diameter of 30 cm...

There is this experiment my high school teacher showed in physics class. You are probably aware of it (from practicalphysics.org) There is a video of a teacher actually doing the experiment here: https://sites.google.com/site/haatscience/physics/221-the-effect-of-inertia Gradually pull the...

Homework Statement A piece of lead of mass 1.5 kg is suspended from a light spring. A copper sphere of mass 2.5 kg is suspended by keans of a thread as attatched to the lead. The thread is then burnt. Calculate the acceleration of each mass at the instant the thread snaps Homework Equations...

I searched for basic GATE aptitude formula derivations and found many useful explanations in this forum. This thread can be used to share such explanations.

I am working on a design where I have a block which has a cap assembly fitted to it - see images attached. The cap assembly is constructed of: - Main body with two holes through (flowing water in and out) - Locking ring with a threaded outside, grooves for tightening by hand and two o-rings...

This thread is for the SULI internship for Fall 2018. The application deadline was May 30th and offers are given until around August 7th. Has anyone had any luck getting accepted to a lab? What labs did you apply to? When did you apply and how long did it take to receive an offer?

Homework Statement Two parallel very long threads are uniformly charged with linear charge density of 10-8 C/cm . Distance between them is 15 cm. Find electric field vector at a distance of 15 cm from both threads. Homework Equations E*dA=Qenclosed/permittivity of free space The Attempt at a...

Hello, Can not Gauss's Law be used to calculate the electric field generated by a uniformly charged finite thread? I suppose it is because I can not consider the electric field constant (always going to the same direction), and for this I would have to do it by parts (the lateral flow, and the...

I'm interested to see what folks think about the BP movie. I just saw it this evening. Personally, I was very impressed by all of the actors except the Black Panther, whom I thought was meh. The general, the little sister, and the bad guy were all particularly outstanding to me. The CGI was...

It is that time of year again. Here's a space to check on acceptances for REU programs or other summer jobs. SULI and SURF come to mind. I imagine most of them will start coming by the end of the month. What are you waiting on? What are you excited for? What do you wish you had applied for? What...

Tell me about your dogs, favorite breeds and share a photo! Here is my 4 year old hound Penny

WARNING! This thread contains spoilers for Star Wars: The Last Jedi. If you have not yet seen the movie, we strongly encourage you to turn around and return once you have. Please use this thread for discussions about The Last Jedi, including spoilers. :smile: I have not seen the movie yet, so I...

Butterfly effect. Much ado about (almost) nothing. Not a lot has to be said to introduce the subject of course. But once before I addressed whether, in reality, a butterfly flapping its wings could actually create a tornado. My view essentially was that the degree of disturbance of the local...