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# Percentage Uncertainties!!!

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1. Needed some help on % uncertainties,
I don't remember the exact question and values, so I'll use random values as an example! It asked to work out "percentage uncertainty" in the highest value of T, in the table provided there were columns of T, time period, so one column was "Time Period Reading 1", second was one "Time Period Reading 2", and 3rd was "Time Period Average". Also in the question we were not given a precision, so from what I know, I'm assuming we firstly have to calculate the "absolute uncertainty" by doing the following calculation.I used 2.34 as an example value.(range of values/2):Time Period 1 - Time Period 2 / 2 = 2.34 <=== Abs. UncertaintyThen working out the "percentage uncertainty" in that, (2.34/Average Reading T)*100?

You couldn't just automatically assume equipment precision as 0.01 could you? As we were given a group of values and not just a single value.
2. The precision would have been however many decimal places the values of T were given, as long as all the values were to the same decimal places. Then yes you can assume 0.01 precision as that is what the time was recorded as and we assume the values were recorded to the precision.
3. (Original post by Aaron98)
The precision would have been however many decimal places the values of T were given, as long as all the values were to the same decimal places. Then yes you can assume 0.01 precision as that is what the time was recorded as and we assume the values were recorded to the precision.
But more than 1 value of T was given? There were 2 reading and an average?
But more than 1 value of T was given? There were 2 reading and an average?
From what I know is that when given multiple values you are required to calculate the absolute uncertainty, and only then can you calculate the % uncertainty? And in the case you mentioned, isn't that only allowed when given a single value of T?
But more than 1 value of T was given? There were 2 reading and an average?
If you have more than one value than you use the range/2 like you did. The precision is still 0.01 but you don't use it, you use the range.
6. For a range of values:
%uncertainty = ((range/2)/average)*100
For one value:
&uncertainty= (precision/value)*100

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