Measure of uncertainty?

[Ryan M]

I thought it was 2*error, however some of the textbook practice problems seem to be using the error itself. Any help would be appreciated!

[Nancy Li 1C]

When for instance, they have that v = 10 +- 2 m/s, since the range of v could be from 8-12 m/s, the ∆v would be 4 m/s (or 2*error). If they say that the uncertainty is 2m/s, ∆v = 2 m/s. For one problem in the textbook, the answer key is wrong and they should be using 2*error.

[Matthew Vu 3C]

If they give an uncertainty and it has the ± symbol, (for example, ∆x = 40±4 m) then you should multiply it by two cause it gives you a range for the error; it can go rom 36-44. However, if they give you an uncertainty, and it's just something like ∆x = 8m, don't multiply it by two.

[Ivan Huang Dis 3B]

think of it as the values within the plus or minus given use that as your uncertainty

[Maleeha Zaman 1K]

Hi Ryan, some problems will straightforward give you the uncertainty, such as atomic diameter, so you would just use this given value as your uncertainty in position. Other cases you will be given atomic radius, in which you will have to multiply by 2 because the atomic diameter will give us the complete uncertainty in position. Or they will give you something like x±Δx, which in this case, you would just use Δx. Hope this helps!