The document discusses errors and accuracy in measurements, defining two main types of errors: random and systematic. Random errors stem from the experimenter and can often be reduced, while systematic errors arise from equipment issues that cannot be easily corrected. It also differentiates between accuracy, the closeness of a measurement to the true value, and precision, the reproducibility of measurements, emphasizing that accuracy is influenced by the experimenter and precision by the instrument used.

1. Physics
Sept 6th, 2023
Topic: Errors and accuracy
Whatever you
do, do it
well

2. Errors

3. What is an error?
A measure of the estimated difference between the observed or
calculated value of a quantity and its true value.
There are two types of errors that are commonly associated with
measuring, (namely),
1. random
2. systematic errors.

4. Random errorr?
Random Errors are errors that are due to the experimenter and can
usually be improved upon.
For example:
a. Reaction time when using the stopwatch
b. Parallax error
c. Errors due to environment

5. Parallax error
Parallax errors occur when
we do not position our eyes
directly above the
measurement we are
reading as so the reading is
slightly off.

6. Systematic Errors
Systematic errors are errors due to the equipment which we are unable to fix or
minimise.
They will be in every reading we measure with the instrument.
For example,
If the stopwatch is 2 seconds fast or the triple beam balance does not zero
properly.
Or when we press the button on the stopwatch, there is a very, very small time
delay for the stopwatch to respond.

7. Precision
&
accuracy

8. Accuracy and precision
Accuracy is the closeness of agreement between a measured value and a true or accepted value. Measurement error is the
amount of inaccuracy.
Precision is a measure of how well a result can be determined (without reference to a theoretical or true value). It is the
degree of consistency and agreement among independent measurements of the same quantity; also the reliability or
reproducibility of the result.
Accuracy depends on the experimenter while precision depends on the instrument.
You cannot be more precise than your instrument.
Nb
Accuracy is how close a value is to the true value
While Precision is the exactness of the value I.e as the unit gets smaller the value gets more precise.

9. precision of an instrument
The metre ruler has a precision of 1mm = 0.1cm
The tbb has a precision of 0.1g
The stopwatch has a precision of 0.01s

10. precision of an instrument
The error associated with any value read from the instrument is 1⁄2 of the
precision.
However the error in a measured value is the precision. Explain.

14. Comment on the accuracy and precision of these
results