Module 2 all Flashcards
Scalar
A quantity that has only magnitude (size) and no direction.
Vector
A quantity that has both magnitude and direction.
Accuracy
A measure of how close a measurement is to the true value
Control Variables
Variables that must remain the same throughout an
experiment so as to not affect the results
Dependent Variables
The variable being measured in an experiment. It is
dependent on the independent variable. The dependent variable should be plotted
on the y-axis of a graph.
Independent Variables
The variable that is changed by the experimenter in an
experiment. The independent variable should be plotted on the x-axis of a graph
Precision
A measure of how close a measurement is to the mean value. It only
gives an indication of the magnitude of random errors, not how close data is to the
true value.
Random Errors
Unpredictable variation between measurements that leads to a
spread of values about the true value. Random error can be reduced by taking
repeat measurements
Repeatable
The same experimenter can repeat a measurement using the same
method and equipment and obtain the same value
Reproducible
An experiment can be repeated by a different experimenter using
a different method and different apparatus, and still obtain the same results.
Resolution
The smallest change in a quantity that causes a visible change in the
reading that a measuring instrument records
SI Units
The standard units used in equations. They are: metres, kilograms,
seconds, amps, Kelvin and moles.
Systematic Errors
Causes all readings to differ from the true value by a fixed
amount. Systematic error cannot be corrected by repeat readings, instead a
different technique or apparatus should be used.
Zero Errors
A form of systematic error, caused when a measuring instrument
doesn’t read zero at a value of zero. This results in all measurements being offset
by a fixed amount
