 #1
DanishForestCat
 5
 0
 Homework Statement:

Hello!
I have a straightforward (I think...) uncertainties problem, that I still can't do. I need to calculate the uncertainty (in seconds) in the deadtime of a Geiger tube.
 Relevant Equations:

The formula for deadtime is (approximately) T = (A+BC)/(2*A*B). A, B and C are all count rates (in counts per second).
A = 209
B = 273
C = 456
I believe that the absolute uncertainty in A is sqrt(A) (I also have a small absolute uncertainty from using a stopwatch).
Does the absolute uncertainty in A+BC equal √A+√B+√C? If so, this is larger than the value of A+BC. Surely that can't be right?
For this investigation, I have been working from a lab script from my local uni physics department. This suggested that calculating this actually required a method using partial derivatives. Is this right? (if so, the calculation would probably be beyond the scope of my course, though if I could work it out, I would obviously use it)
I am really struggling with this, and would be massively grateful for any help.
Many thanks!
For this investigation, I have been working from a lab script from my local uni physics department. This suggested that calculating this actually required a method using partial derivatives. Is this right? (if so, the calculation would probably be beyond the scope of my course, though if I could work it out, I would obviously use it)
I am really struggling with this, and would be massively grateful for any help.
Many thanks!