Percentage transmittance gamma ray through lead

AI Thread Summary
The discussion focuses on calculating the percentage transmittance of gamma rays through lead using the equation I = Io e^-ux. The user initially calculates a value of u as 2.117 but finds a discrepancy in their final answer, which should be 42.2. Other participants suggest checking the calculations, particularly the application of logarithmic rules. The user ultimately realizes their mistake in the logarithmic calculations, leading to the correct understanding. The thread highlights the importance of careful mathematical verification in solving physics problems.
Adam Rabe
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Homework Statement


I = Io e-ux.PNG


Homework Equations


I = Io e^-ux

The Attempt at a Solution


0.75 = 1 * e^-u1
using algebra... u =2.117

I = 1 * e^-2.117*3
I = 0.00175

Answer is apparently 42.2. Can someone tell me where i went wrong? Thanks for any help as always
 
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Adam Rabe said:
0.75 = 1 * e^-u1
using algebra... u =2.117
Check your math. When I put ##e^{-2.117}## into my calculator, I don't get 0.75.
 
Drakkith said:
Check your math. When I put ##e^{-2.117}## into my calculator, I don't get 0.75.
omfg i got it. thanks a lot i derped out with the log rules.
 

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