measurements and errors Flashcards
what is an conversion factor?
A ratio expressing how many of one unit are equal to another unit
What is an error?
The uncertainty we have about our measurements.
What is the formula for the observed value?
true value + error
What are the two types of errors
random and systematic
What is an random error?
An error that follows no set pattern.
What is an systematic error?
An error that follows a set pattern
What could cause an random error?
reading the measuring equipment in different ways
could also be caused by the measuring equipment changing slightly in different ways.
If the experiment was carried out a large number of times.
Define accuracy?
How close a measurement is to the correct value.
Define precision?
How close to each other the repeated measures are.
Define repeatability?
If a measurement is performed by the same person, apparatus and with the same results.
Define reproducibility?
A measurement is reproducible if a different person can perform the same experiment with the same apparatus and get the same results
Define resolution?
The resolution of a measuring instrument describes it’s maximum precision.
What is absolute uncertainty?
The range of possible real values for the length of the string.
What is fractional uncertainty?
It’s the absolute uncertainty divided by the measured value.
What is the percentage uncertainty?
The fractional uncertainty expressed as a percentage
