Solution 19.8d - Revision history

Ian at 17:57, 27 March 2011

Ian — Sun, 27 Mar 2011 17:57:31 GMT

←Older revision		Revision as of 17:57, 27 March 2011
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	The expression for the position vector <math>\mathbf{r}</math> has been obtained in part b).		The expression for the position vector <math>\mathbf{r}</math> has been obtained in part b).

-	<math>\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}</math>	+	<math>\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( {-{t}^{2}}+400 \right)\mathbf{j}</math>

	If the aeroplane is due east of the origin its position in the north-south direction must be zero, which means the <math>\mathbf{j}</math> component of the position vector must be zero.		If the aeroplane is due east of the origin its position in the north-south direction must be zero, which means the <math>\mathbf{j}</math> component of the position vector must be zero.

	<math>\begin{align}		<math>\begin{align}
-	& -2t+400=0 \\	+	& {-{t}^{2}}+400=0 \\
	& \\		& \\
-	& t=~~200~~\text{ s} \\	+	& t=20\text{ s} \\
	\end{align}</math>		\end{align}</math>

Ian at 17:13, 11 October 2010

Ian — Mon, 11 Oct 2010 17:13:14 GMT

←Older revision		Revision as of 17:13, 11 October 2010
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	<math>\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}</math>		<math>\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}</math>
		+
		+	If the aeroplane is due east of the origin its position in the north-south direction must be zero, which means the <math>\mathbf{j}</math> component of the position vector must be zero.
		+
		+	<math>\begin{align}
		+	& -2t+400=0 \\
		+	& \\
		+	& t=200\text{ s} \\
		+	\end{align}</math>

Ian: New page: The expression for the position vector $\mathbf{r}$ has been obtained in part b). $\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}$

Ian — Mon, 11 Oct 2010 17:09:01 GMT

New page: The expression for the position vector <math>\mathbf{r}</math> has been obtained in part b). <math>\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}</math>

New page

The expression for the position vector <math>\mathbf{r}</math> has been obtained in part b).

<math>\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}</math>

Solution 19.8d - Revision history

Ian at 17:57, 27 March 2011

Ian at 17:13, 11 October 2010

Ian: New page: The expression for the position vector \mathbf{r} has been obtained in part b). \mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}

Ian: New page: The expression for the position vector $\mathbf{r}$ has been obtained in part b). $\mathbf{r}=\left( 40t \right)\mathbf{i}+\left( -2t+400 \right)\mathbf{j}$