Transcript Studying Earth Science Chapter Two: The Science Toolbox • 2.1 Measurement • 2.2 Measuring Time and Temperature • 2.3 Systems and Variables • 2.4

Studying Earth Science
Chapter Two: The Science Toolbox
• 2.1 Measurement
• 2.2 Measuring Time and Temperature
• 2.3 Systems and Variables
• 2.4 Graphs
Investigation 2A
S.I. Units
• How can you become more
familiar with SI units?
2.3 Systems and variables
• A system is a group of objects and the
factors that affect these objects.
• The stream table used to model a river is a
system.
What factors affected the stream table system?
2.3 Systems and variables
• A factor that affects an object is called a
variable.
• A system can be affected by many
variables.
What variables
affect this river
system?
2.3 Systems and variables
• In the stream
table system, we
ignored the floor,
temperature,
and light as part
of the system.
What variables were
included in the stream
table system?
2.3 Systems and variables
• The variable that is
changed in an
experiment is the
independent variable.
• The variable that is
affected by the change
to the independent
variable is the
dependent variable.
Which variable is independent?
Which variable is dependent?
2.3 The scale of
a system
•
•
•
One characteristic of all
systems is their scale.
The word scale here
refers to size.
Can you see how scale
changes with these three
views of a road?
2.3 The scale of a system
• Most of the things you
measure in classroom
experiments are large-scale,
or macroscopic.
• Variables are on a large
scale when you can see
them with the naked eye, or
measure them directly.
2.3 Systems and variables
• A model is an
explanation that
connects the
variables in a
system through
cause and effect
relationships.
What does this model help us understand?
2.3 Systems and variables
Science uses many types of models:
– If you wanted to kick a soccer ball into a
goal, you use a mental model to imagine
what the motion looks like.
– A physical model (or scale model) is a
small version of something big.
– A conceptual model is a way of using
your knowledge to understand or
remember a new concept.
– An example of a mathematical model is
2.3 Systems and variables
• Which model does each picture show?
Conceptual model
mathematical
model
Physical model
Investigation 2B
Modeling a River
• Which variables affect the
formation of a river?