4. Krafter och vektorer - Versionshistorik

Taifun den 13 juni 2010 kl. 17.09

Taifun — Sun, 13 Jun 2010 17:09:48 GMT

← Äldre version		Versionen från 13 juni 2010 kl. 17.09
Rad 104:		Rad 104:

	{\| width="100%" cellspacing="10px" align="center"		{\| width="100%" cellspacing="10px" align="center"
-	\|align="left"\| ~~Force~~	+	\|align="left"\| Kraft
-	\| valign="top"\|~~Vector Form~~ (N)	+	\| valign="top"\|Vektorform (N)
	\|-		\|-
	\|20 N		\|20 N
Rad 121:		Rad 121:

	<math>\begin{align}		<math>\begin{align}
-	& \text{~~Resultant Force~~ }=\text{ }\left( 20\cos 50{}^\circ -25\cos 20{}^\circ -15\cos 30{}^\circ \right)\mathbf{i}+\left( 20\sin 50{}^\circ -18-25\sin 20{}^\circ +15\sin 30{}^\circ \right)\mathbf{j} \\	+	& \text{Resultanten }=\text{ }\left( 20\cos 50{}^\circ -25\cos 20{}^\circ -15\cos 30{}^\circ \right)\mathbf{i}+\left( 20\sin 50{}^\circ -18-25\sin 20{}^\circ +15\sin 30{}^\circ \right)\mathbf{j} \\
	& =-23\textrm{.}627\mathbf{i}-3\textrm{.}730\mathbf{j} \ \text{N}		& =-23\textrm{.}627\mathbf{i}-3\textrm{.}730\mathbf{j} \ \text{N}
	\end{align}</math>		\end{align}</math>

Taifun den 13 juni 2010 kl. 17.08

Taifun — Sun, 13 Jun 2010 17:08:00 GMT

← Äldre version		Versionen från 13 juni 2010 kl. 17.08
Rad 8:		Rad 8:


-	== '''~~Key Points~~''' ==	+	== '''Grundbegrepp''' ==

	<math>\begin{align}		<math>\begin{align}
Rad 18:		Rad 18:

	<math>F\cos \alpha </math>		<math>F\cos \alpha </math>
-	~~is one component of the force~~. If <math>\mathbf{i}</math> ~~is horizontal~~,	+	är en komponent av kraften. Om <math>\mathbf{i}</math> är horisontell,
-	<math>F\cos \alpha </math>	+	kallas <math>F\cos \alpha </math> kraftens horisontella komponent.
-	~~is called the horizontal component of the force~~.	+


	<math>F\sin \alpha </math>		<math>F\sin \alpha </math>
-	~~is another component of the force~~. If <math>\mathbf{j}</math> ~~is vertical~~,	+	är kraftens andra komponent. Om <math>\mathbf{j}</math> är vertikal,
-	<math>F\sin \alpha </math>	+	kallas <math>F\sin \alpha </math> kraftens vertikala komponent.
-	~~is called the vertical component of the force~~.	+


-	'''[[~~Example~~ 4.1]]'''	+	'''[[Exempel 4.1]]'''

-	~~Express each of the forces~~ given ~~below in the form~~ a<math>\mathbf{i}</math> + b<math>\mathbf{j}</math>.	+	Skriv varje given kraft nedan på formen a<math>\mathbf{i}</math> + b<math>\mathbf{j}</math>.

	a)		a)
Rad 41:		Rad 39:
	[[Image:TF4.1b.GIF]]		[[Image:TF4.1b.GIF]]

-	'''~~Solution~~'''	+	'''Lösning'''

	a) <math>20\cos 40{}^\circ \mathbf{i}+20\sin 40{}^\circ \mathbf{j}\ \text{N}</math>		a) <math>20\cos 40{}^\circ \mathbf{i}+20\sin 40{}^\circ \mathbf{j}\ \text{N}</math>
Rad 47:		Rad 45:
	b) <math>-80\cos 30{}^\circ \mathbf{i}+80\sin 30{}^\circ \mathbf{j}\ \text{N}</math>		b) <math>-80\cos 30{}^\circ \mathbf{i}+80\sin 30{}^\circ \mathbf{j}\ \text{N}</math>

-	~~Note the negative sign here in the first term~~.	+	Observera det negativa förtecknet i den första termen.


-	'''[[~~Example~~ 4.2]]'''	+	'''[[Exempel 4.2]]'''

-	~~Express the force shown below as a vector in terms of~~ <math>\mathbf{i}</math> ~~and~~ <math>\mathbf{j}</math>.	+	Skriv kraften nedan som en vektor i termer av <math>\mathbf{i}</math> och <math>\mathbf{j}</math>.


	[[Image:TF4.2.GIF]]		[[Image:TF4.2.GIF]]

-	'''~~Solution~~'''	+	'''Lösning'''

	<math>28\cos 30{}^\circ \mathbf{i}-28\sin 30{}^\circ \mathbf{j}\ \text{N}</math>		<math>28\cos 30{}^\circ \mathbf{i}-28\sin 30{}^\circ \mathbf{j}\ \text{N}</math>

-	~~Note the negative sign in the second term~~.	+	Observera det negativa förtecknet i den andra termen.


-	'''[[~~Example~~ 4.3]]'''	+	'''[[Exempel 4.3]]'''

-	~~Express the force shown below as a vector in terms of~~	+	Skriv kraften nedan som en vektor i termer av <math>\mathbf{i}</math> och <math>\mathbf{j}</math>
-	<math>\mathbf{i}</math>	+
-	~~and~~	+
-	<math>\mathbf{j}</math>	+


Rad 75:		Rad 70:


-	'''~~Solution~~'''	+	'''Lösning'''

	<math>-50\cos 44{}^\circ \mathbf{i}-50\sin 44{}^\circ \mathbf{j}\ \text{N}</math>		<math>-50\cos 44{}^\circ \mathbf{i}-50\sin 44{}^\circ \mathbf{j}\ \text{N}</math>

-	~~Note that here both terms are negative~~.	+	Observera att här båda termerna är negativa.
-		+
-		+

-	'''[[Example 4.4]]'''

-	~~Find the magnitude of the force~~ (4<math>\mathbf{i}</math> - 8<math>\mathbf{j}</math>) N. ~~Draw a diagram to show the direction of this force~~.	+	'''[[Exempel 4.4]]'''
		+	Hitta storleken av kraften (4<math>\mathbf{i}</math> - 8<math>\mathbf{j}</math>) N. Rita en bild för att visa denna krafts riktning.

-	'''~~Solution~~'''	+	'''Lösning'''

	[[Image:TF4.4.GIF]]		[[Image:TF4.4.GIF]]


-	~~The magnitude,~~ <math>F</math> ~~, of the force is given by,~~	+	Storleken <math>F</math> av kraften är:

	<math>F=\sqrt{{{4}^{2}}+{{8}^{2}}}=\sqrt{80}=8\textrm{.}94\text{ N (to 3sf)}</math>		<math>F=\sqrt{{{4}^{2}}+{{8}^{2}}}=\sqrt{80}=8\textrm{.}94\text{ N (to 3sf)}</math>


-	~~The angle,~~ <math>\theta </math>~~, is given by,~~	+	Vinkeln <math>\theta </math> är:

	<math>\theta ={{\tan }^{-1}}\left( \frac{8}{4} \right)=63\textrm{.}4{}^\circ </math>		<math>\theta ={{\tan }^{-1}}\left( \frac{8}{4} \right)=63\textrm{.}4{}^\circ </math>


-	'''[[~~Example~~ 4.5]]'''	+	'''[[Exempel 4.5]]'''

-	~~Find the magnitude and direction of the resultant of the four forces shown in the diagram.~~	+	Hitta storleken och riktningen av resultanten till de fyra krafterna på bilden:

	[[Image:TF4.5.GIF]]		[[Image:TF4.5.GIF]]

-	'''~~Solution~~'''	+	'''Lösning'''

	{\| width="100%" cellspacing="10px" align="center"		{\| width="100%" cellspacing="10px" align="center"
Rad 132:		Rad 125:
	\end{align}</math>		\end{align}</math>

-	~~The magnitude is given by~~:	+	Storleken är:

	<math>\sqrt{{{23\textrm{.}627}^{2}}+{{3\textrm{.}730}^{2}}}=23\textrm{.}9\text{ N (to 3sf)}</math>		<math>\sqrt{{{23\textrm{.}627}^{2}}+{{3\textrm{.}730}^{2}}}=23\textrm{.}9\text{ N (to 3sf)}</math>

-	~~The angle~~ <math>\theta </math> ~~can be found using tan.~~	+	Vinkeln <math>\theta </math> kan hittas via tangens:

	<math>\begin{align}		<math>\begin{align}

Tek: flyttade 4. Forces and vectors till 4. Krafter och vektorer

Tek — Mon, 01 Mar 2010 13:58:42 GMT

flyttade 4. Forces and vectors till 4. Krafter och vektorer

← Äldre version

Versionen från 1 mars 2010 kl. 13.58

Ian den 11 februari 2010 kl. 11.41

Ian — Thu, 11 Feb 2010 11:41:03 GMT

← Äldre version		Versionen från 11 februari 2010 kl. 11.41
Rad 43:		Rad 43:
	'''Solution'''		'''Solution'''

-	a) <math>20\cos 40{}^\circ \mathbf{i}+20\sin 40{}^\circ \mathbf{j}</math>	+	a) <math>20\cos 40{}^\circ \mathbf{i}+20\sin 40{}^\circ \mathbf{j}\ \text{N}</math>

-	b) <math>-80\cos 30{}^\circ \mathbf{i}+80\sin 30{}^\circ \mathbf{j}</math>	+	b) <math>-80\cos 30{}^\circ \mathbf{i}+80\sin 30{}^\circ \mathbf{j}\ \text{N}</math>

	Note the negative sign here in the first term.		Note the negative sign here in the first term.
Rad 59:		Rad 59:
	'''Solution'''		'''Solution'''

-	<math>28\cos 30{}^\circ \mathbf{i}-28\sin 30{}^\circ \mathbf{j}</math>	+	<math>28\cos 30{}^\circ \mathbf{i}-28\sin 30{}^\circ \mathbf{j}\ \text{N}</math>

	Note the negative sign in the second term.		Note the negative sign in the second term.
Rad 77:		Rad 77:
	'''Solution'''		'''Solution'''

-	<math>-50\cos 44{}^\circ \mathbf{i}-50\sin 44{}^\circ \mathbf{j}</math>	+	<math>-50\cos 44{}^\circ \mathbf{i}-50\sin 44{}^\circ \mathbf{j}\ \text{N}</math>

	Note that here both terms are negative.		Note that here both terms are negative.
Rad 112:		Rad 112:
	{\| width="100%" cellspacing="10px" align="center"		{\| width="100%" cellspacing="10px" align="center"
	\|align="left"\| Force		\|align="left"\| Force
-	\| valign="top"\|Vector Form	+	\| valign="top"\|Vector Form (N)
	\|-		\|-
	\|20 N		\|20 N
Rad 129:		Rad 129:
	<math>\begin{align}		<math>\begin{align}
	& \text{Resultant Force }=\text{ }\left( 20\cos 50{}^\circ -25\cos 20{}^\circ -15\cos 30{}^\circ \right)\mathbf{i}+\left( 20\sin 50{}^\circ -18-25\sin 20{}^\circ +15\sin 30{}^\circ \right)\mathbf{j} \\		& \text{Resultant Force }=\text{ }\left( 20\cos 50{}^\circ -25\cos 20{}^\circ -15\cos 30{}^\circ \right)\mathbf{i}+\left( 20\sin 50{}^\circ -18-25\sin 20{}^\circ +15\sin 30{}^\circ \right)\mathbf{j} \\
-	& =-23\textrm{.}627\mathbf{i}-3\textrm{.}730\mathbf{j}	+	& =-23\textrm{.}627\mathbf{i}-3\textrm{.}730\mathbf{j} \ \text{N}
	\end{align}</math>		\end{align}</math>

Ian den 29 januari 2010 kl. 14.17

Ian — Fri, 29 Jan 2010 14:17:00 GMT

← Äldre version		Versionen från 29 januari 2010 kl. 14.17
Rad 94:		Rad 94:
	The magnitude, <math>F</math> , of the force is given by,		The magnitude, <math>F</math> , of the force is given by,

-	<math>F=\sqrt{{{4}^{2}}+{{8}^{2}}}=\sqrt{80}=8.94\text{ N (to 3sf)}</math>	+	<math>F=\sqrt{{{4}^{2}}+{{8}^{2}}}=\sqrt{80}=8\textrm{.}94\text{ N (to 3sf)}</math>


	The angle, <math>\theta </math>, is given by,		The angle, <math>\theta </math>, is given by,

-	<math>\theta ={{\tan }^{-1}}\left( \frac{8}{4} \right)=63.4{}^\circ </math>	+	<math>\theta ={{\tan }^{-1}}\left( \frac{8}{4} \right)=63\textrm{.}4{}^\circ </math>


Rad 129:		Rad 129:
	<math>\begin{align}		<math>\begin{align}
	& \text{Resultant Force }=\text{ }\left( 20\cos 50{}^\circ -25\cos 20{}^\circ -15\cos 30{}^\circ \right)\mathbf{i}+\left( 20\sin 50{}^\circ -18-25\sin 20{}^\circ +15\sin 30{}^\circ \right)\mathbf{j} \\		& \text{Resultant Force }=\text{ }\left( 20\cos 50{}^\circ -25\cos 20{}^\circ -15\cos 30{}^\circ \right)\mathbf{i}+\left( 20\sin 50{}^\circ -18-25\sin 20{}^\circ +15\sin 30{}^\circ \right)\mathbf{j} \\
-	& =-23.627\mathbf{i}-3.730\mathbf{j}	+	& =-23\textrm{.}627\mathbf{i}-3\textrm{.}730\mathbf{j}
	\end{align}</math>		\end{align}</math>

	The magnitude is given by:		The magnitude is given by:

-	<math>\sqrt{{{23.627}^{2}}+{{3.730}^{2}}}=23.9\text{ N (to 3sf)}</math>	+	<math>\sqrt{{{23\textrm{.}627}^{2}}+{{3\textrm{.}730}^{2}}}=23\textrm{.}9\text{ N (to 3sf)}</math>

	The angle <math>\theta </math> can be found using tan.		The angle <math>\theta </math> can be found using tan.

	<math>\begin{align}		<math>\begin{align}
-	& \tan \theta =\frac{3.730}{23.627} \\	+	& \tan \theta =\frac{3\textrm{.}730}{23\textrm{.}627} \\
-	& \theta =9.0{}^\circ	+	& \theta =9\textrm{.}0{}^\circ
	\end{align}</math>		\end{align}</math>

	[[Image:TF4.5a.GIF]]		[[Image:TF4.5a.GIF]]

Ian den 29 januari 2010 kl. 13.05

Ian — Fri, 29 Jan 2010 13:05:44 GMT

← Äldre version		Versionen från 29 januari 2010 kl. 13.05
Rad 7:		Rad 7:
	\|}		\|}

		+
		+	== '''Key Points''' ==

	<math>\begin{align}		<math>\begin{align}
Rad 12:		Rad 14:
	& =F\cos \alpha \mathbf{i}+F\sin \alpha \mathbf{j}		& =F\cos \alpha \mathbf{i}+F\sin \alpha \mathbf{j}
	\end{align}</math>		\end{align}</math>
-
-

	[[Image:TF.teori.GIF]]		[[Image:TF.teori.GIF]]
-
-
-
-

	<math>F\cos \alpha </math>		<math>F\cos \alpha </math>
Rad 31:		Rad 27:
	<math>F\sin \alpha </math>		<math>F\sin \alpha </math>
	is called the vertical component of the force.		is called the vertical component of the force.
		+

	'''[[Example 4.1]]'''		'''[[Example 4.1]]'''
Rad 36:		Rad 33:
	Express each of the forces given below in the form a<math>\mathbf{i}</math> + b<math>\mathbf{j}</math>.		Express each of the forces given below in the form a<math>\mathbf{i}</math> + b<math>\mathbf{j}</math>.

-	(a)	+	a)

	[[Image:TF4.1a.GIF]]		[[Image:TF4.1a.GIF]]

-	(b)	+	b)

	[[Image:TF4.1b.GIF]]		[[Image:TF4.1b.GIF]]
Rad 46:		Rad 43:
	'''Solution'''		'''Solution'''

-	(a)	+	a) <math>20\cos 40{}^\circ \mathbf{i}+20\sin 40{}^\circ \mathbf{j}</math>
-		+
-	<math>20\cos 40{}^\circ \mathbf{i}+20\sin 40~~{}^\circ \mathbf{j}</math>~~	+
-		+
-		+
-	~~(b)~~	+
-		+
-	~~<math>-80\cos 30{}^\circ \mathbf{i}+80\sin 30~~{}^\circ \mathbf{j}</math>	+

		+	b) <math>-80\cos 30{}^\circ \mathbf{i}+80\sin 30{}^\circ \mathbf{j}</math>

	Note the negative sign here in the first term.		Note the negative sign here in the first term.


-
	'''[[Example 4.2]]'''		'''[[Example 4.2]]'''

Rad 66:		Rad 56:

	[[Image:TF4.2.GIF]]		[[Image:TF4.2.GIF]]
-

	'''Solution'''		'''Solution'''
-

	<math>28\cos 30{}^\circ \mathbf{i}-28\sin 30{}^\circ \mathbf{j}</math>		<math>28\cos 30{}^\circ \mathbf{i}-28\sin 30{}^\circ \mathbf{j}</math>
-

	Note the negative sign in the second term.		Note the negative sign in the second term.
-


	'''[[Example 4.3]]'''		'''[[Example 4.3]]'''
-

	Express the force shown below as a vector in terms of		Express the force shown below as a vector in terms of
Rad 91:		Rad 76:

	'''Solution'''		'''Solution'''
-		+
-		+
	<math>-50\cos 44{}^\circ \mathbf{i}-50\sin 44{}^\circ \mathbf{j}</math>		<math>-50\cos 44{}^\circ \mathbf{i}-50\sin 44{}^\circ \mathbf{j}</math>
-

	Note that here both terms are negative.		Note that here both terms are negative.
Rad 109:		Rad 92:


-	The magnitude, FN , of the force is given by,	+	The magnitude, <math>F</math> , of the force is given by,

	<math>F=\sqrt{{{4}^{2}}+{{8}^{2}}}=\sqrt{80}=8.94\text{ N (to 3sf)}</math>		<math>F=\sqrt{{{4}^{2}}+{{8}^{2}}}=\sqrt{80}=8.94\text{ N (to 3sf)}</math>
Rad 122:		Rad 105:

	Find the magnitude and direction of the resultant of the four forces shown in the diagram.		Find the magnitude and direction of the resultant of the four forces shown in the diagram.
-

	[[Image:TF4.5.GIF]]		[[Image:TF4.5.GIF]]
-

	'''Solution'''		'''Solution'''
Rad 138:		Rad 119:
	\| 18 N		\| 18 N
	\|valign="top"\| <math>-18\mathbf{j}</math>		\|valign="top"\| <math>-18\mathbf{j}</math>
-
	\|-		\|-
	\| 25 N		\| 25 N
Rad 146:		Rad 126:
	\|valign="top"\|<math>-15\cos 30{}^\circ \mathbf{i}+15\sin 30{}^\circ \mathbf{j}</math>		\|valign="top"\|<math>-15\cos 30{}^\circ \mathbf{i}+15\sin 30{}^\circ \mathbf{j}</math>
	\|}		\|}
-
-
-
-
-
-
-
-
-

	<math>\begin{align}		<math>\begin{align}
Rad 160:		Rad 131:
	& =-23.627\mathbf{i}-3.730\mathbf{j}		& =-23.627\mathbf{i}-3.730\mathbf{j}
	\end{align}</math>		\end{align}</math>
-

	The magnitude is given by:		The magnitude is given by:
-		+
-		+
	<math>\sqrt{{{23.627}^{2}}+{{3.730}^{2}}}=23.9\text{ N (to 3sf)}</math>		<math>\sqrt{{{23.627}^{2}}+{{3.730}^{2}}}=23.9\text{ N (to 3sf)}</math>
-
-

	The angle <math>\theta </math> can be found using tan.		The angle <math>\theta </math> can be found using tan.
-		+
-		+
	<math>\begin{align}		<math>\begin{align}
	& \tan \theta =\frac{3.730}{23.627} \\		& \tan \theta =\frac{3.730}{23.627} \\
	& \theta =9.0{}^\circ		& \theta =9.0{}^\circ
	\end{align}</math>		\end{align}</math>
-

	[[Image:TF4.5a.GIF]]		[[Image:TF4.5a.GIF]]

Ian den 19 maj 2009 kl. 10.34

Ian — Tue, 19 May 2009 10:34:28 GMT

← Äldre version		Versionen från 19 maj 2009 kl. 10.34
Rad 2:		Rad 2:
	{\| border="0" cellspacing="0" cellpadding="0" height="30" width="100%"		{\| border="0" cellspacing="0" cellpadding="0" height="30" width="100%"
	\| style="border-bottom:1px solid #797979" width="5px" \|		\| style="border-bottom:1px solid #797979" width="5px" \|
-	{{Selected tab\|[[2. Forces and vectors\|Theory]]}}	+	{{Selected tab\|[[4. Forces and vectors\|Theory]]}}
-	{{Not selected tab\|[[2. Exercises\|Exercises]]}}	+	{{Not selected tab\|[[4. Exercises\|Exercises]]}}
	\| style="border-bottom:1px solid #797979" width="100%"\|		\| style="border-bottom:1px solid #797979" width="100%"\|
	\|}		\|}

Ian den 15 maj 2009 kl. 10.02

Ian — Fri, 15 May 2009 10:02:24 GMT

← Äldre version		Versionen från 15 maj 2009 kl. 10.02
Rad 130:		Rad 130:

	{\| width="100%" cellspacing="10px" align="center"		{\| width="100%" cellspacing="10px" align="center"
-	\|align="left"\|Force	+	\|align="left"\| Force
	\| valign="top"\|Vector Form		\| valign="top"\|Vector Form
	\|-		\|-
Rad 136:		Rad 136:
	\| valign="top"\| <math>20\cos 50{}^\circ \mathbf{i}+20\sin 50{}^\circ \mathbf{j}</math>		\| valign="top"\| <math>20\cos 50{}^\circ \mathbf{i}+20\sin 50{}^\circ \mathbf{j}</math>
	\|-		\|-
-	\| ~~[[Image:fig b.GIF]]~~	+	\| 18 N
-	\|valign="top"\| ~~Modelling the drum as a particle can explain what happens if the string is horizontal, but not what happens if the string is vertical.~~	+	\|valign="top"\| <math>-18\mathbf{j}</math>
		+
		+	\|-
		+	\| 25 N
		+	\|valign="top"\|<math>-25\cos 20{}^\circ \mathbf{i}-25\sin 20{}^\circ \mathbf{j}</math>
		+	\|-
		+	\| 15 N
		+	\|valign="top"\|<math>-15\cos 30{}^\circ \mathbf{i}+15\sin 30{}^\circ \mathbf{j}</math>
	\|}		\|}


-
-	20 N
-	<math>20\cos 50{}^\circ \mathbf{i}+20\sin 50{}^\circ \mathbf{j}</math>

-	18 N
-	<math>-18\mathbf{j}</math>

-	25 N
-	<math>-25\cos 20{}^\circ \mathbf{i}-25\sin 20{}^\circ \mathbf{j}</math>

-	~~15 N~~	+
-	~~<math>-15\cos 30{}^\circ \mathbf{i}+15\sin 30{}^\circ \mathbf{j}</math>~~	+

Ian den 15 maj 2009 kl. 09.56

Ian — Fri, 15 May 2009 09:56:48 GMT

← Äldre version		Versionen från 15 maj 2009 kl. 09.56
Rad 129:		Rad 129:
	'''Solution'''		'''Solution'''

-	Force Vector Form	+	{\| width="100%" cellspacing="10px" align="center"
		+	\|align="left"\|Force
		+	\| valign="top"\|Vector Form
		+	\|-
		+	\|20 N
		+	\| valign="top"\| <math>20\cos 50{}^\circ \mathbf{i}+20\sin 50{}^\circ \mathbf{j}</math>
		+	\|-
		+	\| [[Image:fig b.GIF]]
		+	\|valign="top"\| Modelling the drum as a particle can explain what happens if the string is horizontal, but not what happens if the string is vertical.
		+	\|}
		+
		+
		+
	20 N		20 N
	<math>20\cos 50{}^\circ \mathbf{i}+20\sin 50{}^\circ \mathbf{j}</math>		<math>20\cos 50{}^\circ \mathbf{i}+20\sin 50{}^\circ \mathbf{j}</math>

Ian den 15 maj 2009 kl. 09.31

Ian — Fri, 15 May 2009 09:31:25 GMT

← Äldre version		Versionen från 15 maj 2009 kl. 09.31
Rad 1:		Rad 1:
		+	__NOTOC__
		+	{\| border="0" cellspacing="0" cellpadding="0" height="30" width="100%"
		+	\| style="border-bottom:1px solid #797979" width="5px" \|
		+	{{Selected tab\|[[2. Forces and vectors\|Theory]]}}
		+	{{Not selected tab\|[[2. Exercises\|Exercises]]}}
		+	\| style="border-bottom:1px solid #797979" width="100%"\|
		+	\|}
		+
		+
	<math>\begin{align}		<math>\begin{align}
	& \mathbf{F}=F\cos \alpha \mathbf{i}+F\cos (90-\alpha )\mathbf{j} \\		& \mathbf{F}=F\cos \alpha \mathbf{i}+F\cos (90-\alpha )\mathbf{j} \\

← Äldre version		Versionen från 19 maj 2009 kl. 10.34
Rad 2:		Rad 2:
	{\| border="0" cellspacing="0" cellpadding="0" height="30" width="100%"		{\| border="0" cellspacing="0" cellpadding="0" height="30" width="100%"
	\| style="border-bottom:1px solid #797979" width="5px" \|		\| style="border-bottom:1px solid #797979" width="5px" \|
-	{{Selected tab\|[[2. Forces and vectors\|Theory]]}}	+	{{Selected tab\|[[4. Forces and vectors\|Theory]]}}
-	{{Not selected tab\|[[2. Exercises\|Exercises]]}}	+	{{Not selected tab\|[[4. Exercises\|Exercises]]}}
	\| style="border-bottom:1px solid #797979" width="100%"\|		\| style="border-bottom:1px solid #797979" width="100%"\|
	\|}		\|}