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The Relationship between Variables.
The way in which the
variables change is called
the relationship between the
variables.
The relationship can be linear,
directly proportional or non-linear.
Linear just means that the two
variables give a straight line
graph.
For example, the distance -
time graphs of a stationary object
and an object moving with constant
velocity are both linear.
Directly
proportional means that the rate of increase in
one variable
is the same as the rate of increase in
the other variable.
If you double one thing, the other
thing doubles.
For example, the braking
distance of a car
is directly
proportional to its mass.
Non-linear means that
the rate of increase in one variable
is not the same as the rate of
increase in the other variable.
For example, the braking
distance of a car
has a non-linear relationship to its velocity.
Enzyme
activity has a non-linear
relationship to temperature.
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