Average and Uncertainty and Error Bars

1. Average and Uncertainty

The first step for typical data is to average the data, and find the trial to trial uncertainty.

For HL Physics, the expectation is that we derive trial to trial uncertainty by simply taking half the range of the trials:

(High - Low)

        2

in the spreadsheet, the two functions I use are

=average(B14:F14)

where B14:F14 is just the range in the spreadsheet where my trials happen to be for that variation.

and

=(  max(B14:F14)  -  min(B14:F14)  )/2

where the functions max() and min() simply return the maximum and minimum of the given range.  Notice the nested parenthesis.

Here is an example video

Do the same thing with the data in the spreadsheet (Tab Ex 1)

2. Graphs with Error Bars:

Notice:

• • The axes are labeled with units

  • The graph has a title

  • There is a trend line, and the equation is displayed.

  • The graph axes include the origin (0,0) and extend enough to give room for the points and error bars

  • There are adequate gridlines to read max and min slope endpoints (More on that later)

  • The points include individually sized error bars

Here is an example of how to do this: (it isn't pretty with Google Sheets - this is a workaround)

Keep in mind that when you are done with your graph, you will need to screenshot it into your document.