Uncertainty in Newton's law of cooling

AI Thread Summary
The discussion focuses on calculating the uncertainty in the cooling constant k using Newton's law of cooling, given temperature uncertainties of +/- 0.5 degrees. The user seeks clarification on the uncertainty of the natural logarithm of the temperature difference and how to incorporate this into the calculation of k. Different approaches to uncertainty are highlighted, with an emphasis on using standard deviations and root-sum-square methods for a scientific perspective. The conversation also touches on the need to find the uncertainty in the exponential term e^(-kt). The thread ultimately aims to clarify the correct method for determining k's uncertainty in the context of temperature measurements.
sunmoonlight
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Homework Statement
Uncertainty in Newton's law of cooling
Relevant Equations
T(t) = = 𝑇_𝐴+(𝑇_𝑜−𝑇_𝐴)𝑒^(−𝑘𝑡)
I'm finding the uncertainty of k, given that each temperature has an uncertainty of +/- 0.5 degress.
 
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sunmoonlight said:
Homework Statement: Uncertainty in Newton's law of cooling
Relevant Equations: T(t) = = 𝑇_𝐴+(𝑇_𝑜−𝑇_𝐴)𝑒^(−𝑘𝑡)

I'm finding the uncertainty of k, given that each temperature has an uncertainty of +/- 0.5 degress.
You will also need approximate values for the temperatures.
Per forum rules, please show some attempt.
 
say the T(O) = 90 +/- 0.5, T(t): 60 +/- 0.5, TA = 10 +/- 0.5, temp difference (T(t) - TA) is 50 degrees +/- 0.5, t= 100s
1. Is the uncertainty for ln (T(t) - TA) = 1/2*(ln50.5 - ln49.5) = +/-0.01?
2. If you substitute the values into the eqt, you get k = (ln50/80)/-100, so what's the uncertainty for k (like how do you find uncertainty involving logs?)
 
sunmoonlight said:
say the T(O) = 90 +/- 0.5, T(t): 60 +/- 0.5, TA = 10 +/- 0.5, temp difference (T(t) - TA) is 50 degrees +/- 0.5, t= 100s
1. Is the uncertainty for ln (T(t) - TA) = 1/2*(ln50.5 - ln49.5) = +/-0.01?
2. If you substitute the values into the eqt, you get k = (ln50/80)/-100, so what's the uncertainty for k (like how do you find uncertainty involving logs?)
There are different concepts of uncertainty. An engineer worried about engineering tolerances would just look at the combinations of the extreme values. A scientist would take the given uncertainties as standard deviations in normal distributions and use root-sum-square approaches to combine them. I assume you are looking for the latter.

Can you find the uncertainty in ##e^{-kt}##?
 
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