Block walking - Revision history

en>Emily McCullough: Undid revision 597350376 by Emily McCullough (talk)

2014-03-06T09:42:07Z

Undid revision 597350376 by Emily McCullough (talk)

← Older revision		Revision as of 11:42, 6 March 2014
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	~~Hello and welcome. My~~ name is ~~Numbers Wunder~~. ~~[http://hopesvoice.org/events/does-hiv-look-like-~~me~~/ California] is exactly where her home~~ is ~~but she at home std test needs~~ to ~~move simply because of her family members. For years he's been operating as a [http://women.webmd.com/features/could-you-have-std-not-know meter reader]~~ and it'~~s something at home std test he [http://xrambo.com/blog/191590 std testing at home] truly enjoy. The factor she adores most is body developing and now she is~~ attempting to make money with it.<br><br>Here is my ~~std home [http://www.pornextras.info/user/G49Z home std test] test~~ web page: [http://~~glskating~~.com/~~groups/stay-yeast-infection-free-with-these-helpful-suggestions/ http://glskating.com~~/]		The name of the writer is Figures. One of the extremely very best things in the globe for me is to do aerobics and now I'm attempting to make money with it. Hiring has been my profession for some time but I've already applied for an additional one. North Dakota is our birth place.<br><br>Here is my web page; [http://riddlesandpoetry.com/?q=node/19209 std testing at home]

en>Emily McCullough: I changed the introduction completely; I omitted the reference to Pascal's triangle and defined block walk and (NE) lattice path.

2014-02-27T09:41:01Z

I changed the introduction completely; I omitted the reference to Pascal's triangle and defined block walk and (NE) lattice path.

← Older revision		Revision as of 11:41, 27 February 2014
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	~~{{underlinked\|date=October 2012}}~~		Hello and welcome. My name is Numbers Wunder. [http://hopesvoice.org/events/does-hiv-look-like-me/ California] is exactly where her home is but she at home std test needs to move simply because of her family members. For years he's been operating as a [http://women.webmd.com/features/could-you-have-std-not-know meter reader] and it's something at home std test he [http://xrambo.com/blog/191590 std testing at home] truly enjoy. The factor she adores most is body developing and now she is attempting to make money with it.<br><br>Here is my std home [http://www.pornextras.info/user/G49Z home std test] test web page: [http://glskating.com/groups/stay-yeast-infection-free-with-these-helpful-suggestions/ http://glskating.com/]
	~~[[File:Gee-haw whammy diddle~~.~~gif\|thumb\|Spinning gee-haw whammy diddle]]~~
	~~[[Image:GeeHawWhimmyDiddle.JPG\|thumb\|right\|210px\|The gee-haw whammy diddle~~.~~]]<!-- Deleted image removed:~~ [~~[Image~~: ~~Gee-Haw Whammy Diddle~~.~~jpg\|thumb\|right\|210px\|The gee~~-~~haw whammy diddle.]]~~ -->
	~~A '''gee~~-~~haw whammy diddle''' is a [[Mechanical system\|mechanical]] toy consisting of two wooden sticks. One has a series of notches cut transversely along its side and a smaller wooden stick or a [[propeller]~~] ~~attached to the end with a nail or pin. This stick~~ is ~~held stationary in one hand with the notches up, and the other stick~~ is ~~rubbed rapidly back and forth across the notches. This causes the propeller~~ to ~~rotate~~. ~~Sometimes also known~~ as a ~~'''~~[~~[ouija]] windmill''', a '''hooey stick''' or a '''VooDoo stick'''~~. ~~The word ''whammy'' is sometimes ''whimmy'' and the word ''diddle'' sometimes ''doodle'', giving it three possible other names, and the ''gee~~-~~haw'' may also be dropped.~~

	~~''[[Gee and haw\|Gee~~-~~haw]~~]~~'' refers to the fact that, by rubbing your finger against the notched stick while rubbing, the direction of the spinning propeller may be reversed. The operator may do this surreptitiously~~ and ~~yell "gee" or "haw" to make it appear that the propeller is reacting to the commands. If you call~~ it a '~~'hooey stick'', you would yell "hooey" each time you want the direction to change.~~

	~~==Physical explanation==~~
	~~To observe the effect, the propeller attached to the end of the ribbed stick must not be pinned~~ at ~~its exact~~ [~~[centre of mass]]~~. ~~For a functioning whammy diddle, there should be a "preferred" [[angle]~~] (i.~~e. when stationary, if the propeller~~ is ~~rotated around its axis~~ and then released, it should return to its lowest-energy [[rest angle]] relative to the ribbed stick.) Rubbing the ribbed stick with another stick along the grooves creates a vertical alternating driving [[force]] <math>F_y</math> acting on the centre of mass of the propeller:

	~~:<math> F_y(t) = Y cos(\omega t) </math>~~

	~~where <math>h \omega = 2\pi/T </math> and T~~ is ~~the time taken for the stick~~ to ~~move from one groove to the next; <math>Y</math> is some unknown scaling factor that characterizes the force~~ with ~~which the two sticks are pressed against one another~~. ~~By rubbing a finger against these grooves on the side, one can also introduce a ''horizonal'' alternating driving force~~ <~~math~~>~~F_x~~<~~/math~~>

	:~~<math> F_x(t) = X cos(\omega t + \phi) <~~/~~math>~~

	~~where <math>\phi<~~/math> is a [[phase shift]] (describing the lag time between when the grooves contacts the moving rod, and finger respectively) and, again, X is some unknown scaling factor. Importantly, <math>\omega</math> is the ''same'' frequency, and the two driving forces are said to be [[phase locked loop\|phase locked]]. ~~The confluence of two phase matched driving forces in [[Orthogonality\|orthogonal]] directions gives rise to a [[rotational force]] on the centre of mass at the propeller end, and thus, rotation~~.

	~~When the operator of the whammy-diddle surreptitiously changes the side at which his~~/her finger contacts the stick (e.g. by contacting with his thumb instead of his fore-finger, or by changing the side at which a finger contacts the grooves of the base) he or she changes the sign of the phase <math>\phi</~~math>, and thus reverses the rotation.~~

	~~==See also==~~
	* [[Whirligig]]

	~~==References==~~
	* [http://~~www.mugwumps~~.com/~~whammy.htm "Toys, Making a Whammy Diddle"], ''MUGWUMPS'', Vol. 1, No. 6, November 1972.~~
	* {{cite journal
	~~\|last=Aubrecht~~
	~~\|first=Gordon J., II.~~
	~~\|title=A mechanical toy: The gee~~-~~haw whammy~~-~~diddle~~
	~~\|journal=The Physics Teacher~~
	~~\|volume=20 \|issue= 9\|date=December 1982 \|pages=614–615~~
	~~\|bibcode=1982PhTea..20..614A~~
	~~\|doi=10.1119/1.2341165~~
	}}

	~~==Further reading==~~
	* Schnacke, Dick. ''American Folk Toys: How to Make Them,'' Viking Press, 1974. (ISBN 0-14-~~046209~~-0)

	~~{{DEFAULTSORT:Gee~~-~~Haw Whammy Diddle}}~~
	~~[[Category~~:~~Traditional toys]]~~
	~~[[Category:Wooden toys]~~]

en>Rayvenz: /* Solution by Brute Force */ added details to my method

2013-03-04T01:53:18Z

Solution by Brute Force: added details to my method

← Older revision		Revision as of 03:53, 4 March 2013
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	The ~~author~~ is ~~called Irwin Wunder but~~ it'~~s not~~ the ~~most masucline name out there~~. ~~Puerto Rico~~ is ~~exactly where he~~'~~s usually been living but she requirements~~ to ~~move because~~ of ~~her family~~. ~~My working day occupation~~ is a ~~librarian~~. ~~Playing baseball~~ is the ~~hobby he will by no means stop doing~~.<br><br>~~Have~~ a ~~look~~ at ~~my webpage~~ ... [http://www.~~hotporn123~~.com/~~user/RPocock http~~:/~~/www~~.~~hotporn123~~.~~com/user/RPocock~~]		{{underlinked\|date=October 2012}}
			[[File:Gee-haw whammy diddle.gif\|thumb\|Spinning gee-haw whammy diddle]]
			[[Image:GeeHawWhimmyDiddle.JPG\|thumb\|right\|210px\|The gee-haw whammy diddle.]]<!-- Deleted image removed: [[Image: Gee-Haw Whammy Diddle.jpg\|thumb\|right\|210px\|The gee-haw whammy diddle.]] -->
			A '''gee-haw whammy diddle''' is a [[Mechanical system\|mechanical]] toy consisting of two wooden sticks. One has a series of notches cut transversely along its side and a smaller wooden stick or a [[propeller]] attached to the end with a nail or pin. This stick is held stationary in one hand with the notches up, and the other stick is rubbed rapidly back and forth across the notches. This causes the propeller to rotate. Sometimes also known as a '''[[ouija]] windmill''', a '''hooey stick''' or a '''VooDoo stick'''. The word ''whammy'' is sometimes ''whimmy'' and the word ''diddle'' sometimes ''doodle'', giving it three possible other names, and the ''gee-haw'' may also be dropped.

			''[[Gee and haw\|Gee-haw]]'' refers to the fact that, by rubbing your finger against the notched stick while rubbing, the direction of the spinning propeller may be reversed. The operator may do this surreptitiously and yell "gee" or "haw" to make it appear that the propeller is reacting to the commands. If you call it a ''hooey stick'', you would yell "hooey" each time you want the direction to change.

			==Physical explanation==
			To observe the effect, the propeller attached to the end of the ribbed stick must not be pinned at its exact [[centre of mass]]. For a functioning whammy diddle, there should be a "preferred" [[angle]] (i.e. when stationary, if the propeller is rotated around its axis and then released, it should return to its lowest-energy [[rest angle]] relative to the ribbed stick.) Rubbing the ribbed stick with another stick along the grooves creates a vertical alternating driving [[force]] <math>F_y</math> acting on the centre of mass of the propeller:

			:<math> F_y(t) = Y cos(\omega t) </math>

			where <math>h \omega = 2\pi/T </math> and T is the time taken for the stick to move from one groove to the next; <math>Y</math> is some unknown scaling factor that characterizes the force with which the two sticks are pressed against one another. By rubbing a finger against these grooves on the side, one can also introduce a ''horizonal'' alternating driving force <math>F_x</math>

			:<math> F_x(t) = X cos(\omega t + \phi) </math>

			where <math>\phi</math> is a [[phase shift]] (describing the lag time between when the grooves contacts the moving rod, and finger respectively) and, again, X is some unknown scaling factor. Importantly, <math>\omega</math> is the ''same'' frequency, and the two driving forces are said to be [[phase locked loop\|phase locked]]. The confluence of two phase matched driving forces in [[Orthogonality\|orthogonal]] directions gives rise to a [[rotational force]] on the centre of mass at the propeller end, and thus, rotation.

			When the operator of the whammy-diddle surreptitiously changes the side at which his/her finger contacts the stick (e.g. by contacting with his thumb instead of his fore-finger, or by changing the side at which a finger contacts the grooves of the base) he or she changes the sign of the phase <math>\phi</math>, and thus reverses the rotation.

			==See also==
			* [[Whirligig]]

			==References==
			* [http://www.mugwumps.com/whammy.htm "Toys, Making a Whammy Diddle"], ''MUGWUMPS'', Vol. 1, No. 6, November 1972.
			* {{cite journal
			\|last=Aubrecht
			\|first=Gordon J., II.
			\|title=A mechanical toy: The gee-haw whammy-diddle
			\|journal=The Physics Teacher
			\|volume=20 \|issue= 9\|date=December 1982 \|pages=614–615
			\|bibcode=1982PhTea..20..614A
			\|doi=10.1119/1.2341165
			}}

			==Further reading==
			* Schnacke, Dick. ''American Folk Toys: How to Make Them,'' Viking Press, 1974. (ISBN 0-14-046209-0)

			{{DEFAULTSORT:Gee-Haw Whammy Diddle}}
			[[Category:Traditional toys]]
			[[Category:Wooden toys]]

en>Paul A: /* Combinatorial Solution */ link repair (You can help!)

2009-08-21T09:10:39Z

Combinatorial Solution: link repair (You can help!)

New page

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