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#### John Robbo

##### New member

- Feb 16, 2014

- 2

- Thread starter John Robbo
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- #1

- Feb 16, 2014

- 2

- Feb 5, 2012

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Hi John Robbo,I have attempted the questions in the attached sheet could someone check if the answers are correct.

View attachment 1985

1. + = 1.28

- = -0.69

2. Transposed to

t = ln (P/Po) -5 / 1.2

t= -3.18

3. x = 0

x = 2.5

4. t= -0.125

s= 10.7

Thanks

Welcome to MHB!

The first and third and fourth answers are correct. For the fourth answer I get \(t=-0.127\) when rounded to three decimal places.

In the third answer you have messed up with a minus sign.

\[p=p_0 e^{5-1.2t}\]

\[\Rightarrow \ln\left(\frac{p}{p_0}\right)=5-1.2t\]

\[\Rightarrow t=\frac{1}{1.2}\left(5-\ln\left(\frac{p}{p_0}\right)\right)\]

which gives you, $t=3.18$.

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- #3

- Feb 16, 2014

- 2

sudharaka thanks for your help understand where I went wrong

- Feb 5, 2012

- 1,621

You are welcome.sudharaka thanks for your help understand where I went wrong