1) If I place an object on a table, it will sit there forever. There's no change in potential or kinetic energy.  If I hold the object at the end of my outstretched arm, eventually I can't do it anymore. But the object is still not changing kinetic/potential energy.  Where is the loss coming from?  2) Related question: An airplane is flying level in the air. How much power is needed to keep it level?  It seems clear that any explanation will revolve around inefficiency in the force-providing mechanism, something to do with how your muscles work for the first question and something to do with drag in the airplane example.
I read the definition of  as  $$W ~=~ \vec{F} \cdot \vec{d}$$  $$\text{ Work  =  (Force) $\cdot$ (Distance)}.$$ If a book is there on the table, no work is done as no distance is covered. If I hold up a book in my hand and my arm is stretched, if no work is being done, where is my energy going?
I am getting these warnings every time I update my initramfs image(-s) with  on my Dell PowerEdge T20 server running    10.0. Is there a fix?    W: Possible missing firmware /lib/firmware/i915/bxt_dmc_ver1_07.bin for module i915 W: Possible missing firmware /lib/firmware/i915/skl_dmc_ver1_27.bin for module i915 W: Possible missing firmware /lib/firmware/i915/kbl_dmc_ver1_04.bin for module i915 W: Possible missing firmware /lib/firmware/i915/cnl_dmc_ver1_07.bin for module i915 W: Possible missing firmware /lib/firmware/i915/glk_dmc_ver1_04.bin for module i915 W: Possible missing firmware /lib/firmware/i915/kbl_guc_ver9_39.bin for module i915 W: Possible missing firmware /lib/firmware/i915/bxt_guc_ver9_29.bin for module i915 W: Possible missing firmware /lib/firmware/i915/skl_guc_ver9_33.bin for module i915 W: Possible missing firmware /lib/firmware/i915/kbl_huc_ver02_00_1810.bin for module i915 W: Possible missing firmware /lib/firmware/i915/bxt_huc_ver01_07_1398.bin for module i915 W: Possible missing firmware /lib/firmware/i915/skl_huc_ver01_07_1398.bin for module i915 How can I run everything as root I have dual booted to lubuntu (with Windows XP) and everytime and then I'm getting asked for my password. How do I run everything as root and not ask a password again? Ideally I wanted to run nginx but it has permission denied issues:  apathetic@ubuntu:~$ service nginx start Starting nginx: nginx: [alert] could not open error log file: open() "/var/log/nginx/error.log" failed (13: Permission denied) 2012/08/03 20:06:25 [warn] 4762#0: the "user" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:1 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok 2012/08/03 20:06:25 [emerg] 4762#0: open() "/var/run/nginx.pid" failed (13: Permission denied) nginx: configuration file /etc/nginx/nginx.conf test failed Detect when an iOS app is launched for the first time? How do I detect when an iOS app is launched for the first time? How to close ports in Linux? I have some question in closing port, I think I got some strange things.  When I use execute  nmap --top-ports 10 192.168.1.1   it shows that 23/TCP port is open.  But when I execute  nmap --top-ports 10 localhost   it show that 23/tcp port is closed.  Which of them is true? I want to close this port on my whole system, how can I do it? "Each of these is" vs. "each of these are" Each of these CDFIs are finding solutions for communities that lack   access to traditional financial products and services, and the NEXT   Awards will accelerate their success.   OR     Each of these CDFIs is finding solutions for communities that lack   access to traditional financial products and services, and the NEXT   Awards will accelerate their success.   The difference is, the first one uses "CDFIs are" and the 2nd sentence uses "CDFIs is"  Which one is correct? Any why? In Star Wars: "The Force Awakens," how could this lightsaber have turned up where it did? In The Force Awakens:      Maz Kanata tells Rey that the lightsaber she just picked up and had visions from belonged to Anakin and Luke and now it's hers.   The lightsaber that Luke got from Obi-Wan Kenobi in A New Hope was lost/destroyed when Luke fought Darth Vader in Star Wars: The Empire Strikes Back.  In Return of the Jedi Darth Vader compliments Luke on building a new lightsaber and tells Luke that his skills are now complete.   How could that possibly be the lightsaber that Anakin used originally, and that was then passed on to Luke, when that lightsaber no longer exists?  Writers notes, director's notes, interviews, cast interviews, etc. are welcome. Thanks. How can Innodb ibdata1 file grows by 5X even with innodb_file_per_table set? I have innodb_file_per_table set and just today my ibdata1 file jumped from 59M to 323M after I made several changes to an 800M table to reduce it to about 600M. That particular table's .ibd file was reduced but the server's ibdata1 file went crazy. Any ideas? I need to cast single figures (1 to 9) to (01 to 09). I can think of a way but its big and ugly and cumbersome. I'm sure there must be some concise way. Any Suggestions Why does the wire-frame material fades across the object? Why does the wire-frame material fades across the object?  Here is what I did - I created a new material and I selected on "Wire" and I made it shadeless. Then, I created a new material and assigned the new material on the on the object. However, doing it that way, it allows me to render both materials - "Wire" and "Surface". Then I get a fading result like this -    But I want all of the edges to be shown, not a fading result. How can I make that?  Here is the blend file if anybody wants to check it out - Legitimate edits of less than 6 characters Given two equivalent norms, convergence in one implies convergences in other. Suppose we have two equivalent norms, $\|\cdot \| \sim \left\vert\!\left\vert\!\left\vert \cdot\right\vert\!\right\vert\!\right\vert$. We assume that $x_n \rightarrow x $ in $(X,\|\cdot \|)$. Show that $x_n \rightarrow x $ in $(X,\left\vert\!\left\vert\!\left\vert \cdot\right\vert\!\right\vert\!\right\vert)$  We observe since the norms are equivalent, there exits constants $\alpha, \beta$, such that $\alpha \|\cdot \| \leq \left\vert\!\left\vert\!\left\vert \cdot\right\vert\!\right\vert\!\right\vert \leq \beta \|\cdot \|$, with $0 \lt \alpha \leq \beta$  Since, $x_n \rightarrow x$ in $(X,\|\cdot \|$) we know that for all $\epsilon&gt;0, \exists K(\epsilon)$ such that for n>$K(\epsilon),$ we have $\|x_n -x\| \leq \epsilon$  Since, we know $\beta \gt 0$ , then $ \beta \|x_n -x\| \leq \beta \epsilon$, Thus we see that $\left\vert\!\left\vert\!\left\vert x_n-x\right\vert\!\right\vert\!\right\vert\leq \beta \epsilon$.  This is how far I've gotten, our goal to is to find a a $J(\epsilon)$ such that for all $\epsilon&gt;0, \exists J(\epsilon)$ such that for n>$J(\epsilon),$ we have $\left\vert\!\left\vert\!\left\vert x_n-x \right\vert\!\right\vert\!\right\vert \leq \epsilon$  My candidate for $J(\epsilon$) is $J(\epsilon) = \frac{K(\epsilon)}{\beta}$ from my above argument, but I'm not exactly sure how to validate this. If someone could help me on the proof, it would be very appreciated. I believe I'm pretty close, just missing something small. Extract float/double value How do I extract a double value from a string using regex.  import re  pattr = re.compile(???)     x = pattr.match("4.5") Out-of-control starship results in some crew members landing in a rebirthed universe? I've got this situation:  ./ ./myscript.sh ./arguments.txt ./test.sh   Inside myscript.sh, I have to run the file test.sh, passing to it the arguments contained inside arguments.txt.  myscript.sh is:  arguments=$(cat arguments.txt) source test.sh $arguments   This works well if if arguments.txt contains at most one argument:  firstargument    The substitution is:  ++ source test.sh 'firstargument'   But the problem is with two or more arguments. It does this:  ++ source test.sh 'firstargument secondargument'   Also, I don't know in advance the number of arguments inside arguments.txt. There can be zero or more. I was wondering if there is a name for a function that satisfies the conditions  $f:\mathbb{R} \to \mathbb{R}$ and $f(x+y)=f(x) \cdot f(y)$?  Thanks and regards! Proper way to Plot a single function in two different styles? Why Can't I duck reverb on the mix bus in Unity? i'm surprised there is so little documentation on this issue. But i'm trying to duck the audio on all the mix buses in Unity so that you can clearly hear the VO of the game.  Now it works great except that I have some reverb zones in the game and any sound that plays in these reverb zones, the actual reverb itself is NOT DUCKED.  So the VO is accompanied with a huge wall of wishy washy muddy noise.  Anyone deal with this before? How can we deal with this? NSInvocation for Dummies? How exactly does NSInvocation work? Is there a good introduction?  I’m specifically having issues understanding how the following code (from Cocoa Programming for Mac OS X, 3rd Edition) works, but then also be able to apply the concepts independently of the tutorial sample. The code:  - (void)insertObject:(Person *)p inEmployeesAtIndex:(int)index {     NSLog(@"adding %@ to %@", p, employees);     // Add inverse of this operation to undo stack     NSUndoManager *undo = [self undoManager];     [[undo prepareWithInvocationTarget:self] removeObjectFromEmployeesAtIndex:index];     if (![undo isUndoing])         [undo setActionName:@"Insert Person"];      // Finally, add person to the array     [employees insertObject:p atIndex:index]; }  - (void)removeObjectFromEmployeesAtIndex:(int)index {     Person *p = [employees objectAtIndex:index];     NSLog(@"removing %@ from %@", p, employees);     // Add inverse of this operation to undo stack     NSUndoManager *undo = [self undoManager];     [[undo prepareWithInvocationTarget:self] insertObject:p                                        inEmployeesAtIndex:index];     if (![undo isUndoing])         [undo setActionName:@"Delete Person"];      // Finally, remove person from array     [employees removeObjectAtIndex:index]; }   I get what it’s trying to do. (BTW, employees is an NSArray of a custom Person class.)  Being a .NET guy, I try to associate unfamiliar Obj-C and Cocoa concepts to roughly analogous .NET concepts. Is this similar to .NET’s delegate concept, but untyped?   This isn’t 100% clear from the book, so I’m looking for something supplemental from real Cocoa/Obj-C experts, again with the goal that I understand the fundamental concept beneath the simple(-ish) example. I'm really looking to be able to independently apply the knowledge -- up until chapter 9, I was having no difficulty doing that. But now ...    Thanks in advance! Is it acceptable to use "whose" when referring to an object? Whose is used for people (e.g. "Whose that girl?"), but is it acceptable to use whose for objects too? Is there another word I should use for objects?  To make the question clearer, when I ask "Whose that car?" I am expecting an answer similar to "It's X's car." where X refers to a person. I could say "a man whose opinion I respect." and whose opinion would refer to the opinion of a person. Could I say "the desk whose drawer was broken by my brother"? Should I replace whose with another word? Ramanujan Summation It seems that under the light of  the following is plausible:  $$1 + {2^{2n - 1}} + {3^{2n - 1}} +  \cdots  =  - \frac{{{B_{2n}}}}{{2n}}(\Re)$$  Alas, I can't really find any concrete definition of Ramanujan Summation. Could someone provide a small explanation?