A REVIEW OF VARIABLES
UNIT 1
SIXTH GRADE SCIENCE
THE VARIABLE UNIVERSE
• What is a variable?
• A variable is anything that you can change that might
affect the outcome of an experiment.
• Examples:
• In a car: body size and shape, tire size and shape, weight, fuel type,
and color
• In a house: shape, number of rooms, wall colors. Floor type, number
of windows
HOW DO WE DETERMINE THE
BEHAVIOR OF VARIABLES?
• Experimentation –
• A scientist will investigate the effect variable have by
conducting an experiment.
MORE TERMS TO KNOW
• Controlled experiment – When you change one variable
at a time and keep all the other variables the same.
• System – A set of objects that is working together.
• Pendulum – Any mass suspended on a string, rope, or
other arm that is free to pivot from an anchor point
• Cycle – A complete rotation; for example, one
complete swing back and forth
• Independent Variable – The variable whose value
determines the dependent variable. This is found along
the x-axis on a two-coordinate graph.
• Dependent Variable – a variable that is determined
based on the independent variable. This is found along
the y-axis on a tow-coordinate graph.
MORE TERMS TO KNOW
• Buoyancy – the ability to rise and float in a fluid.
• Capacity – The maximum volume of fluid a
container can hold.
• Displacement – the fluid pushed out of a way when
and object is placed in the fluid. (mass of the
displaced fluid = the mass of the object placed in
the fluid)
INVESTIGATION 1: SWINGERS
• What were the variables for the pendulum?
• The length of the string
• The release position
• The mass at the end of the string
• Which variable affected the number of swings?
• The length of the string
• We found that as the length of the pendulum increases, the number
of swings in a unit of time decreases. As the pendulum decreases,
the number of swings in a unit of time increases.
• How do we show the relationship between the number
of swings in a given time and the length of the swing?
• We use a two-coordinate graph, which also helps us make
predictions.
INVESTIGATION 2: LIFEBOATS
• What variables affected the number of passengers
supported by a boat?
•
•
•
•
Size of the boat
Placement of the passengers into the boat
Where the passengers were placed
Condition of the sea
• What did we find out?
• The larger the capacity of a boat, the greater the number
of passengers it can hold.
• A two-coordinate graph can be used to make
predictions.
INVESTIGATION 3: PLANE SENSE
• What are the parts of a model plane system?
• Propellers, crafts sticks, rubber bands, straws, hook, the flight
line, and the launch technique.
• What are the variables in this lab?
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•
•
•
•
The size of the rubber band
The number of winds on the rubber band
The number of paper clips carried by the plane
The slope of the line
The manner in which the airplane is launched
• A two-coordinate graph displays the relationship
between an experimental variable and an
outcome.
INVESTIGATION 4: FLIPPERS
• What are the parts of the flipper system?
• A flexible flip stick, a base, and the object launched.
• What are the variables in this lab?
• The mass of the object flipped
• The angle of the flipper system
• The length of the flip stick
• Graphs can be used to look for errors, make
predictions, and understand the relationship
between a variable and an outcome.
LET’S PRACTICE
• If you were trying to show the relationship between
the number of pennies needed to sink a boat and
the capacity of the boat, while other variable are
controlled, which graph represents this? (X-axis is
capacity, Y axis is number of passengers) Explain.
A
B
C
D
LET’S PRACTICE
• If you created a graph to show the relationship
between the distance a model plane can fly and
the mass of the plane, where all other variables are
controlled, what would it look like? (X-axis is mass, Yaxis is distance flown). Explain your answer.
A
B
C
D
WHAT TO STUDY??
• As you prepare for the exam, you should review the
following items several times:
• This PowerPoint
• All your class notes
• Your lab worksheets and notes
Do not wait until the night before to begin studying…if you
prepare a little each day, you will do well. This is a 40 point
exam.