Flashcards in Working as a physicist Deck (20):
What is uncertainty?
The interval in which the true value lies/the range of possible values
What is the error in a result?
The difference between the measured value and the true value
What is % uncertainty?
The uncertainty calculated as a percentage of the measured value
What is resolution?
The smallest measuring interval in a single reading. Resolution can give the uncertainty, but for instruments such as a stopwatch, human reaction time also contributes to uncertainty, so resolution cannot give uncertainty
What is the range?
The largest value minus the smallest value (in repeated readings)
What is precision?
Indicates the consistency between repeated values
Why is it better to measure larger values?
A larger value will give a much smaller percentage uncertainty, assuming the uncertainty is fixed
How should you estimate the uncertainty for a single measurement?
Given by half the smallest increment on the device. However, for instruments such as a ruler, the increment is the uncertainty, as 2 measurements are made.
How should you estimate the uncertainty for repeated readings?
Uncertainty is half the range, and % uncertainty is half range divided by mean
For calculated values, how should you combine uncertainties?
Add the % uncertainties (generally while multiplying or dividing results)