The Standard
Simple Pendulum Exemplar
Bouncing Mass exemplar
This next exemplar (left) is taken straight from NCEA. Although it is a different experiment, it is useful to give some indication of the level of critical thinking required for excellence in the discussion.
On the left is a spreadsheet you can use to check your data processing. Open it in Excel, save a copy and type in your data. It will process your data and draw some graphs as well as give you an equation for your best fit line. |
Half Range Rule
This section is taken from: http://mrwhibley.weebly.com/uncertainties-in-measurements.html
Use this rule when the greatest source of uncertainty is not from your equipment.
(for example when using stop watch and user reaction time is the greatest source of uncertainty)
"If there are multiple measurements, the absolute uncertainty is half of the range of the measurements"
Example:
The amount of time taken for a pendulum to swing back and forth is recorded multiple times. The times recorded are...
1.42s, 1.37s, 1.40s, 1.42s, 1.40s, 1.39s, 1.37s
The range of these measurements is: 1.42s - 1.37s = 0.05s
The absolute uncertainty is half of this: (0.05s)/2 = 0.025s = 0.03s (1sf)
The average of these measurements is 1.396s = 1.40s (rounding to 2dp, the same as the uncertainty)
Our complete value with absolute uncertainty is:
Time = 1.40 ± 0.03s
Use this rule when the greatest source of uncertainty is not from your equipment.
(for example when using stop watch and user reaction time is the greatest source of uncertainty)
"If there are multiple measurements, the absolute uncertainty is half of the range of the measurements"
Example:
The amount of time taken for a pendulum to swing back and forth is recorded multiple times. The times recorded are...
1.42s, 1.37s, 1.40s, 1.42s, 1.40s, 1.39s, 1.37s
The range of these measurements is: 1.42s - 1.37s = 0.05s
The absolute uncertainty is half of this: (0.05s)/2 = 0.025s = 0.03s (1sf)
The average of these measurements is 1.396s = 1.40s (rounding to 2dp, the same as the uncertainty)
Our complete value with absolute uncertainty is:
Time = 1.40 ± 0.03s
Error Bars |
Accuracy vs. Precision |