Whenever we define a physical quantity, we know what 1 unit of that quantity tells us. For example, when we say 5 Pa, we're saying 5 N force acts perpendicularly on every unit area of the material but I've never been able to understand this for moment of force. What is 1 N$\cdot$m exactly telling me?
As a 8th grader I am still a newbie at science and I have problems understanding the forces that I can not imagine and one of these "forces" is the moment.  We are told that,  $$\text{moment}= Nm$$ but how can a certain force (i.e. $N$) be applied when there is $m$? How does it depend on the length of the considered object?  And how can 1 moment be defined on the basis of that representation?  And what would be the effect if the moment value is increased by the newton part as opposed to the effect when the value is increased by the length part.  Or is the result the same in both cases?
How do you add a certificate authority (CA) to Ubuntu? Convert bytes to a string I'm using this code to get standard output from an external program:  &gt;&gt;&gt; from subprocess import * &gt;&gt;&gt; command_stdout = Popen(['ls', '-l'], stdout=PIPE).communicate()[0]   The communicate() method returns an array of bytes:  &gt;&gt;&gt; command_stdout b'total 0\n-rw-rw-r-- 1 thomas thomas 0 Mar  3 07:03 file1\n-rw-rw-r-- 1 thomas thomas 0 Mar  3 07:03 file2\n'   However, I'd like to work with the output as a normal Python string. So that I could print it like this:  &gt;&gt;&gt; print(command_stdout) -rw-rw-r-- 1 thomas thomas 0 Mar  3 07:03 file1 -rw-rw-r-- 1 thomas thomas 0 Mar  3 07:03 file2   I thought that's what the  method is for, but when I tried it, I got the same byte array again:  &gt;&gt;&gt; binascii.b2a_qp(command_stdout) b'total 0\n-rw-rw-r-- 1 thomas thomas 0 Mar  3 07:03 file1\n-rw-rw-r-- 1 thomas thomas 0 Mar  3 07:03 file2\n'   How do I convert the bytes value back to string? I mean, using the "batteries" instead of doing it manually. And I'd like it to be OK with Python&nbsp;3. Script to remove certain span elements from an HTML file What does: Error Broken count >0 mean? I have the message:   Error Broken count &gt;0 Check if you are using third party repositories. If so disable them, since they are a common source of problems. Furthermore run the following command in a Terminal: apt-get install -f Details: The following packages have unmet dependencies: firefox-globalmenu: Depends: firefox (= 19.0+build1-0ubuntu0.12.04.2) but 19.0+build1-0ubuntu0.12.04.1 is installed   Any suggestions? Say I create an object thus:  var myObject =         {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};   What is the best way to retrieve a list of the property names? i.e. I would like to end up with some variable 'keys' such that:  keys == ["ircEvent", "method", "regex"] Undercooked beans in chili? I made a bit of a mistake, being a lazy bachelor and inexperienced at cooking.  I was making chili and when it came time to add beans I discovered I didn't have any canned beans.  I did however have some dried beans.  I decided to save time and add these directly to the pot of chili and add some water.  However, after much simmering the beans maintain a certain unpalatable crispness.  I have also read that undercooked beans contain a chemical lectin which can cause stomach discomfort.  I have also read that beans should be soaked, the water discarded to remove the lectin, and then boiled to cook them.  Is there any way to salvage this?  Should I just continue cooking the chili for hours?  Will I have to throw out my potentially delicious chili? As the title says. I use, among other things, the following in my lstset:  framerule=1pt, frame=tblr   Some places a page break happens in the middle of my \lstlisting. Fine. But sometimes the whole code of the listing appears on one page, but the bottom frame appears on the top of the next page!    I know that I can float a particular listing, but I have a long document with many listings, and I don't want to float all of them; Most of them also need to be exactly where they are declared. That they are broken over a page doesn't bother me that much.  Is there something that can stop this from happening, without me needing to adjust each individual listing?   had the same problem, but fixed it by removing spaces in front of keywords in a custom language definition. I too have a custom language definition, but his solution doesn't help me. I managed to recreate the situation without a custom language.  Edit and MWE  I managed to reproduce it in a minimal working example. 's a pastebin, if that's helpfull.  \documentclass[UKenglish,a4paper,11pt]{report} \usepackage{babel}  %% Adjustments \addtolength{\topmargin}{-1\baselineskip} \addtolength{\textheight}{4\baselineskip} \pretolerance = 2000 \tolerance = 5000   \hbadness = \tolerance  %% Smaller font \usepackage{mathptmx}  %% LISTINGS \usepackage[final]{listings} \lstset{     xleftmargin=1.5em,     framexleftmargin=1em,     framextopmargin=0.5ex, %%  THE FRAME:     framerule=1pt,     frame=tblr }  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  \usepackage{lipsum}     % for demo \begin{document} \subsubsection{Lorem}   % some fiddling to get the "wrong spacing just right": \lipsum[1-3] \subsubsection{Ipsum}  \lipsum[1] and then some text  \begin{lstlisting} Here is a listing with three lines of code; The bottom border is placed on the next page! \end{lstlisting}  Can you believe it..?! \end{document}   This MWE is rather long. My document inputs most of the listings stuff from files written by others, so I'm not sure what all of it does. If anyone sees some lines that they are sure is irrelevant, feel free to take it out of the MWE.  "Fun fact"  An equally silly situation occurs if you remove \usepackage{mathptmx}: The whole code listing will then appear on the new page, except for the top frame which is left on the bottom of the first page! How do I re-position the displayed image on my laptop? I want to re-position the display on my ASUS K53SM laptop's screen because I somehow managed to damage some portion of it (and I don't want to spend on this laptop for the time being).  Please refer the following image:    I changed the resolution from 1366x768 to 1280*768 to avoid the bad portion of the screen, but the screen is now centered and the right portion of my screen is now rendered useless.  What I want to do is, set a custom resolution of my laptop and re-position it in a way that is utilizes all the working area of my screen.  How do I re-position the displayed image on my laptop? I made an svg in Illustrator, but now I want to use it in a website/app but it's a huge size (around 10 MB) how can I decrease the size of it? My illustrator file is pretty big but that because I have some tracing elements underneath. The file also has a big artboard, but when I save should I delete my tracing elements, and decrease the artboard size? Is "architect" a verb and a noun? I hear the word architect used as a verb in the technical field and now more often in other industries and groups, for example:     We need to architect a better solution to the problem.   I am interested if this is considered acceptable usage, as I see this word being used more in published technical documents (not necessarily books, but corporate publications).  I can see how a conductor can conduct, a typist can type, but can a scientist "science"?  A scientist might research, analyze, and so forth, as an architect might design, create, build, etc.  Merriam-Webster , however, I have been told that other dictionaries exist that define architect as both a noun and a verb&nbsp;— is there a credible reference or source that authoritatively answers this question? HTML5 Canvas to PNG File Do I need an ESTA to enter the US with the Victoria Clipper ferry? I am thinking of visiting Victoria, BC in Canada and then going to Seattle, WA in the US, with the .  I am a national of a country under the Visa Waiver Program. I think that if I enter by air, I need to fill an ESTA form. If I enter by car, I don't need one, I can fill a form when crossing the border.  With the ferry, what is the procedure? Should I necessarily have an ESTA? How do I reset all progress in the game "just shapes and beats"? The game  has a very unique intro that I would like to show my friend again for the first time. I'm not sure how to reset all my progress on this game to achieve this though. Any thoughts? Can I possibly recover the Windows system partition that I deleted (100MB)? After moving to SSD I deleted the System Partition (100MB) from my previous drive, causing mass destruction.  I tried to delete the System Partition which windows 7 creates (on my previous disc as I moved to SSD) and when I tried to extend the main partition size to include the new Unallocated Space it asked me if I wanted to convert the disc to Dynamic.  I simply pressed yes and the partition simply disappeared into unallocated space. All of my family pictures / videos lost.  After reading an article on Microsoft they said to recreate the partition with the same exact size, so I tried to do that but it didn't work. I did not format the drive at all when I created partitions.  How can I possibly recover the partitions?  Thanks! When to delete your 0 vote answers? I've been in the SO community a little over a month now - and having a great time!  As I grow into a contributing citizen of stackoverflow, i'd like to ensure that i'm being responsible with my answers.   I've answered a few questions, some without upvotes, some voted on and some accepted.  I feel that after a certain period of time, 0 vote answers are probably providing more clutter than value.  Apparently, nobody has found them useful, so they probably aren't (or are poorly written). Tonight I went through and deleted my answers with 0 upvotes where some answer was accepted.  That was an easy decision.   I left my 0 vote answers where nothing was accepted yet, well, because I think they could provide the information that the OP requested.  But at some point, I think my answers might just be cluttering the issue.  So my question to you is: How do you know when it's time to delete your 0 vote answers?  Or even 1 vote answers for that matter? let $a,b,c,d,e$ are positive real numbers,show that $$\dfrac{a-b}{b+c}+\dfrac{b-c}{c+d}+\dfrac{c-d}{d+e}+\dfrac{d-e}{e+a}+\dfrac{e-a}{a+b}\ge 0$$  My try:  I have solved follow Four-variable inequality:  let $a,b,c,d$ are positive real numbers,show that $$\dfrac{a-b}{b+c}+\dfrac{b-c}{c+d}+\dfrac{c-d}{d+a}+\dfrac{d-a}{a+b}\ge 0$$ poof:since \begin{align*} &amp;\dfrac{a-b}{b+c}+\dfrac{b-c}{c+d}+\dfrac{c-d}{d+a}+\dfrac{d-a}{a+b}=\dfrac{a+c}{b+c}+\dfrac{b+d}{c+d}+\dfrac{c+a}{d+a}+\dfrac{d+b}{a+b}-4\\ &amp;=(a+c)\left(\dfrac{1}{b+c}+\dfrac{1}{d+a}\right)+(b+d)\left(\dfrac{1}{c+d}+\dfrac{1}{a+b}\right)-4 \end{align*} By Cauchy-Schwarz inequality we have $$\dfrac{1}{b+c}+\dfrac{1}{d+a}\ge\dfrac{4}{(b+c)+(d+a)},\dfrac{1}{c+d}+\dfrac{1}{a+b}\ge\dfrac{4}{(c+d)+(a+b)}$$ so we get $$\dfrac{a-b}{b+c}+\dfrac{b-c}{c+d}+\dfrac{c-d}{d+a}+\dfrac{d-a}{a+b}\ge\dfrac{4(a+c)}{(b+c)+(d+a)}+\dfrac{4(b+d)}{(c+d)+(a+b)}-4=0$$ Equality holds for $a=c$ and $b=d$  By done!  But for  Five-variable inequality,I can't prove it.Thank you What are the rules for animal mating? How do I set up SSH so I don't have to type my password? How do I set up SSH so I don't have to type my password when connecting to a host? How to evaluate $\lim\limits_{n\to+\infty} \prod\limits_{k=1}^n (1+k/n^2)$? I've got a limit which puzzle me several days. The question is  $$ \lim_{n\to+\infty} \prod_{k=1}^n\left(1+\frac{k}{n^2}\right).$$  Can you help me? Thank you in advance How to use (home) brew install python 3.6.5_1 I am trying to install python 3.6.5_1 using Homebrew by running the following:  $ brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/f2a764ef944b1080be64bd88dca9a1d80130c558/Formula/python.rb   I am getting the following error:  Error: python contains a recursive dependency on itself: python depends on sphinx-doc sphinx-doc depends on python   How do I deal with it?