Calculate L using Omega, Lo = 16, and h = 1.5

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To find L using the equation ω = (1/h) ln(L/Lo - 1) with given values ω = -2.6, Lo = 16, and h = 1.5, the calculations lead to L = 16.32384. The discussion highlights the importance of using the correct notation for natural logarithms and suggests that substituting constants later in the process can help avoid round-off errors. An alternative method for solving the equation is provided, emphasizing a clearer algebraic manipulation. Overall, the solution is confirmed as correct, and the importance of notation and method is reinforced.
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Find L if...

Homework Statement



\omega=\frac{1}{h}In(\frac{L}{Lo}-1)

Find L if omega - -2.6, Lo = 16 and h = 1.5

Homework Equations





The Attempt at a Solution



-2.6*1.5=In(L/16-1)
-3.9=In(L/16-1
e^-3.9=L/16-1
0.02024=L/16-1
1.02024=L/16
so L=16.32384
 
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The correct abbreviation for the natural log is 'lower case L' and 'lower case N'. You have 'Upper case I' and 'lower case N', which is incorrect. Otherwise, your algebra appears to be correct.
 
SteamKing said:
The correct abbreviation for the natural log is 'lower case L' and 'lower case N'. You have 'Upper case I' and 'lower case N', which is incorrect. Otherwise, your algebra appears to be correct.

Ok thanks for the help I will use the correct abbreviation in future
 
eddievic said:

Homework Statement



\omega=\frac{1}{h}In(\frac{L}{Lo}-1)

Find L if omega - -2.6, Lo = 16 and h = 1.5

Homework Equations


The Attempt at a Solution



-2.6*1.5=In(L/16-1)
-3.9=In(L/16-1
e^-3.9=L/16-1
0.02024=L/16-1
1.02024=L/16
so L=16.32384

It's best to substitute the constants at the end of your algebraic manipulation. Doing so sooner can lead to round-off errors.

This is the way I would have done it.
$$\omega=\frac{1}{h}\ln(\frac{L}{L_0}-1)$$
$$\Rightarrow h \omega = \ln(\frac{L}{L_0}-1)$$
$$\Rightarrow e^{h \omega} = \frac{L}{L_0}-1$$
$$\Rightarrow e^{h \omega} + 1 = \frac{L}{L_0}$$
$$\Rightarrow L_0 (e^{h \omega} + 1) = L$$
Now you can replace the constants.
 
Mark44 said:
It's best to substitute the constants at the end of your algebraic manipulation. Doing so sooner can lead to round-off errors.

This is the way I would have done it.
$$\omega=\frac{1}{h}\ln(\frac{L}{L_0}-1)$$
$$\Rightarrow h \omega = \ln(\frac{L}{L_0}-1)$$
$$\Rightarrow e^{h \omega} = \frac{L}{L_0}-1$$
$$\Rightarrow e^{h \omega} + 1 = \frac{L}{L_0}$$
$$\Rightarrow L_0 (e^{h \omega} + 1) = L$$
Now you can replace the constants.

this makes a lot of sense thanks Mark44
 
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