I thought the uncertainty was always half the smallest measurement so, since using the ruler, the smallest measurement it can do is 1mm there will always be an uncertainty of +/- 0.5mm each side for any measurement. And for the calipers it's 0.005mm either side which adds up to 0.01mm. But why if the voltmeter and stopwatch can read 0.01 is the uncertainty 0.01? Shouldn't it be 0.005? I don't understand, is the uncertainty just the smallest measurement then?
+Bob Rouf Great question. My understanding (especially based on the way the OCR look at uncertainties) is that for an analogue scale the uncertainty is to half the smallest scale division which in the case of a ruler is +/- 0.5 mm at each end so +/-1mm like you said. For a digital scale the uncertainty is the smallest scale division on the measuring instrument. That's the guidance I was given when I queried this with the exam board and that is what they are expecting students to use.
fatma faisal It is minimum value which can be read by measuring device. In a meter ruler even if minimum division on scale is 1mm we can measure to 0.5mm (half the distance ). In any digital meter(or meter/scale with very fine/small divisions) we can't measure half of minimum division, since we cant see it. So we take the minimum value measurable.
Why uncertainty is written like +-1mm or 0.01cm of meter rod rather +- 0.5mm I don't get BC we all know that the reading could be 0.5mm away or below .
@@puregaming8726 In a ruler, as it is a measurement, it is +-0.5 mm at either end of the object you are measuring. There is a +-0.5mm uncertainty at the zero mark and at the other end.
+mumblebopp Excellent question (and one that is still very much open to debate). The latest info I received directly from the exam board is that for a digital instrument then there isn't an error at the start of the measurement.
I thought the uncertainty was always half the smallest measurement so, since using the ruler, the smallest measurement it can do is 1mm there will always be an uncertainty of +/- 0.5mm each side for any measurement. And for the calipers it's 0.005mm either side which adds up to 0.01mm.
But why if the voltmeter and stopwatch can read 0.01 is the uncertainty 0.01? Shouldn't it be 0.005? I don't understand, is the uncertainty just the smallest measurement then?
+Bob Rouf Great question. My understanding (especially based on the way the OCR look at uncertainties) is that for an analogue scale the uncertainty is to half the smallest scale division which in the case of a ruler is +/- 0.5 mm at each end so +/-1mm like you said. For a digital scale the uncertainty is the smallest scale division on the measuring instrument. That's the guidance I was given when I queried this with the exam board and that is what they are expecting students to use.
I found this comment more helpful than the video. At least you explained how you got your numbers. Blathering on with answers and zero explanations.
That's quite mean don't you think...
Your question and his answer cleared my fuking confusion...
Thanks sunny...
@@user-ed5ug9jw7v rude much :/
Thank you kind sir for your helpful video
for measuring time, what if you use a slow motion video?
i just dont get it.. how do we know if the absolute uncertainty is 1 or 0.5?
fatma faisal It is minimum value which can be read by measuring device. In a meter ruler even if minimum division on scale is 1mm we can measure to 0.5mm (half the distance ).
In any digital meter(or meter/scale with very fine/small divisions) we can't measure half of minimum division, since we cant see it. So we take the minimum value measurable.
Why uncertainty is written like +-1mm or 0.01cm of meter rod rather +- 0.5mm I don't get BC we all know that the reading could be 0.5mm away or below .
@@puregaming8726 In a ruler, as it is a measurement, it is +-0.5 mm at either end of the object you are measuring. There is a +-0.5mm uncertainty at the zero mark and at the other end.
ikr
Yo u cant tell me this is all there is to it.. my teacher b over complicating stuff for no reason smh
Same here 😅
Will this be the same for all exam boards?
of course
Is there always uncertainty at the start of a measurement? e.g If we start at 0 seconds on at stopwatch.
+mumblebopp Excellent question (and one that is still very much open to debate). The latest info I received directly from the exam board is that for a digital instrument then there isn't an error at the start of the measurement.
lewis i hope you been recycling all this paper,
Of course!