What happens to kinetic energy of an object when I stop its motion? Assume an object is moving and it is stopped at a point. Now kinetic energy will transform into some other energy. What can be those energies and on which cases these will happen respectively?  Furthermore, when that kinetic energy of an object (going upward against gravity) transforms into potential energy, the net potential energy of the object will be more than $mgh$ (where height is $h$ with respect to base). Is this fact correct? How can this unusual energy amount make sense?
Where does the energy required to stop a moving body come from and go? For a long time, I have been thinking about this: In order to stop a moving body, I have to apply impulse to change the existing momentum to $0$. For the impulse I have to impart force on the moving body . That means I have to eliminate all the kinetic energy associated with the moving object in order to bring it to a halt. Thus, work is done on the object, right? If work is done, energy must be given by me...  Here is where my confusion arises:   If I eliminate the associated kinetic energy of the body, where does this energy go? The work(?) done by me on the moving object to stop it obviously uses energy from me. Again, where does this energy go?
I would like to configure my Ubuntu 12.04 server to synchronize its clock with a specific NTP server. Where to set this up? The origin of spin is some what a puzzle to me, everything spin from galaxies to planets to weather to electrons.  Where has all the angular momentum come from? Why is it so natural?  I was also thinking do photons spin? we always think of the wave as a standard 2d sin wave but could this rotate in 3d? What implications would this have?   And what about spacetime how does all the spinning effect?  This has always been avoided in all lectures and classes I ever went to. Can I mention professors' names in the statement of purpose? For PhD applications, I have mentioned that I am interested in some research areas. Besides, I am thinking about mentioning some professors' names, so that it shows I have read their websites and I am not just sending out generic statements applicable to many schools.  But is it good to mention some professors' names in the statement of purpose, if I don't know them personally? In what cases is it good, and in what cases it isn't?  For example, is it good to only mention    those whose research directions are aligned with my research interests, or/and those whose books or notes I have heard of, or better, might have read some parts of, or/and those who are already established and famous (such as having certain titles), or/and those that are directing the PhD graduate programs, or/and those that are heads of the departments?    What will other professors who are not mentioned think? How will you do, if it were you? How to read dash files What is the purpose of the thin wire at the top of power transmission lines? I know a power transmission line carries usually two sets of 3 phase conductors. But I have noticed a relatively thin wire at the center-top of the power transmission line. What is the purpose of this thin wire? How to create a grain / noise effect in Adobe Illustrator I want to create a noise effect using Adobe Illustrator.  Inside the hexagonal shape there is some kind of texture effect, I don't know what the name of this effect is:    How can I create such an effect in Adobe Illustrator? or is it created using Photoshop? Does equality of characteristic polynomials guarantee equivalence of matrices? I have a qualifying exam coming up in a couple days and I am just trying to understand some pathological examples I have in my notes. I will list a similar problem which I know the solution to and then the question.  True or False:   let $A,B \in \mathbb{Q}^{n \times n }$  Suppose $xI-A$ and $xI-B$ are equivalent then $\det(xI-A) = \det(xI-B)$.     I wrote in my notes this is true because any two matrices are equivalent in $\mathbb{Q[x]}^{n \times n}$ if and only if they have the same invariant factors.  Since the characteristic polynomial is a product of the invariant factors it follows that $\det(xI-A) = \det(xI-B)$.        True or False:   let $A,B \in \mathbb{Q}^{n \times n }$. If $\det(xI-A) = \det(xI-B)$ (in $\mathbb{Q}[x]$) then $xI-A$ and $xI-B$ are equivalent  in $\mathbb{Q}[x]^{n \times n}$   I think this is false because of the fact that equality of determinants is not strong enough to guarantee all invariant factors are equal but I do not have an example. Relative pronouns "where" and "when": where can they be omitted? I know the "omitting-rules" regarding the relative pronouns who/which/that and whose. How does it work with where and when? In the first sentence I cannot omit where but I can easily omit when in the second sentence. What is the rule?   I saw John in the shop where you bought your brown T-shirt. I met Laura on the day (when) I missed the train to Barcelona. Project Euler - 34 / Find a mathematical approach for upper bound 145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145. Find   the sum of all numbers which are equal to the sum of the factorial of   their digits. Note: as 1! = 1 and 2! = 2 are not sums they are not   included.   So I tried a random enough large upper bound (100000) in my program and it worked.  I deleted this part to not spoil the answer  My question is : How to find the closest upper bound using a mathematical approach ? Windows file system is case insensitive. How, given a file/folder name (e.g. "somefile"), I get the actual name of that file/folder (e.g. it should return "SomeFile" if Explorer displays it so)?  Some ways I know, all of which seem quite backwards:   Given the full path, search for each folder on the path (via FindFirstFile). This gives proper cased results of each folder. At the last step, search for the file itself. Get filename from handle (as in ). This requires opening a file, creating file mapping, getting it's name, parsing device names etc. Pretty convoluted. And it does not work for folders or zero-size files.   Am I missing some obvious WinAPI call? The simplest ones, like GetActualPathName() or GetFullPathName() return the name using casing that was passed in (e.g. returns "program files" if that was passed in, even if it should be "Program Files").  I'm looking for a native solution (not .NET one). Identify this 80's movie about a force-field shaped like a bubble What's the best and quickest way to detect whether you're running a 32 or 64-bit version of Windows Server from the command line?  (Cygwin is installed) How can I resize NTFS partition in GParted? Variable number of arguments in C++? Delete all data for a kind in Google App Engine I would like to wipe out all data for a specific kind in Google App Engine. What is the best way to do this? I wrote a delete script (hack), but since there is so much data is timeout's out after a few hundred records. I'm having exactly the same issue as , also using Biber 2.14, albeit I didn't upgrade, downgrade, change TexLive version, change encoding or (seemingly) do anything. It's like Biber suddenly quit parsing dates on me.  Whether the bibfile is encoded in ASCII or UTF-8 makes no difference. Whether the date is a short format or the full YYYY-MM-DD makes no difference. I'm not sure what else to test.  Here's a MWE and the associated .blg file:  \begin{filecontents}{mwe.bib}     @Article{JD2020,         author       = {John Doe},         title        = {A Title},         date         = {2020-01-01},         %date       = {2020}         journaltitle = {Journal},     } \end{filecontents}  \documentclass{article} \usepackage{biblatex} \addbibresource{mwe.bib}  \begin{document}     test\autocite{JD2020}     \printbibliography \end{document}   [1] Config.pm:304&gt; INFO - This is Biber 2.14 [1] Config.pm:307&gt; INFO - Logfile is 'mwe.blg' [154] biber-darwin:322&gt; INFO - === Thu Apr 30, 2020, 11:04:33 [185] Biber.pm:415&gt; INFO - Reading 'mwe.bcf' [354] Biber.pm:943&gt; INFO - Found 1 citekeys in bib section 0 [384] Biber.pm:4256&gt; INFO - Processing section 0 [385] Utils.pm:75&gt; INFO - Globbing data source 'mwe.bib' [385] Utils.pm:91&gt; INFO - Globbed data source 'mwe.bib' to mwe.bib [401] Biber.pm:4455&gt; INFO - Looking for bibtex format file 'mwe.bib' for section 0 [402] bibtex.pm:1653&gt; INFO - LaTeX decoding ... [406] bibtex.pm:1471&gt; INFO - Found BibTeX data source 'mwe.bib' [437] Utils.pm:304&gt; WARN - Entry 'JD2020' (mwe.bib): Invalid format '2020-01-01' of date field 'date' - ignoring [457] UCollate.pm:68&gt; INFO - Overriding locale 'en-US' defaults 'normalization = NFD' with 'normalization = prenormalized' [457] UCollate.pm:68&gt; INFO - Overriding locale 'en-US' defaults 'variable = shifted' with 'variable = non-ignorable' [457] Biber.pm:4084&gt; INFO - Sorting list 'nty/global//global/global' of type 'entry' with template 'nty' and locale 'en-US' [457] Biber.pm:4090&gt; INFO - No sort tailoring available for locale 'en-US' [461] bbl.pm:652&gt; INFO - Writing 'mwe.bbl' with encoding 'UTF-8' [463] bbl.pm:755&gt; INFO - Output to mwe.bbl [463] Biber.pm:128&gt; INFO - WARNINGS: 1   The \printbibliography output actually looks like this: [1] John Doe. “A Title”. In: Journal ().  In my actual thesis, all the dates are gone from the pdf output. How to cleanly launch a GUI app via the Terminal? Some GUI apps launch cleanly via the Terminal command line, but some don't, and they cause the Terminal to wait for the app to terminate. Even then, some don't "release" the command line.  The mysterious ampersand &amp; suffix seems to cause the terminal to put the process into the background (but I'm not sure what happens there).  Is there a way to launch an app via the Terminal so that there is no "hang on" effect, just like launching something via Alt+F2?  I'd like to have the command line available again immediately, without something still in the background and printing in the terminal. How to set security options for a PDF using pdflatex My questions is very simple. How can I set security setting for a PDF file created with PDFLatex?  I should set some password or print permissions, etc. What happens when ability scores reach 0? D&amp;D 5E does not seem to have rules for ability score damage (that I could find), although it does mention that if CON is decreased, your maximum HP is reduced. In addition, the Shadow monster in the Monster Manual has a Strength Drain attack that deals 2 Strength damage. The attack says that if a character's Strength reaches 0, the character dies. Are there any general rules for ability damage in 5th Edition? View revision history on mobile site It looks like it's currently not possible to view the revision history of a post from the mobile site. I think it would be a lot simpler than loading the desktop site on a phone just to get the revision history.