Students learn how to identify and control variables in an
experiment with pendulums. They
systematically change the variables of mass, release position, and length of
string to determine which variables will affect the number of swings in 15
seconds. Students also learn to
graph experiment results on a two-coordinate graph.

**Word
Bank:
**

Pendulum—a
mass hanging from a fixed point that is free to swing to and fro | |

Cycle—any
motion or activity that repeats itself | |

Variable—anything
that you can change in an experiment that might affect the outcome | |

Standard—the
basic procedure used in a controlled experiment, before changing any of the
variables | |

Controlled
experiment—an experiment in which one, and only one, variable is
changed in order to assess its effect | |

Two-coordinate
graphs—shows the outcome of a series of experiments when a variable is
changed by steps |

**Study
Questions:
**

What is a variable? | |

What is a pendulum and where have you seen one? | |

What variables might affect the number of cycles the pendulum makes in 15 seconds? | |

Which variables made no difference in the number of swings? | |

Which variable did make a difference in the number of swings? | |

Is there a relationship between the length of a pendulum and the number of swings it makes in a unit of time? |

Students continue to identify and control variables in an
experiment with lifeboats. They
construct lifeboats out of paper cups and then fill them with penny passengers.
They change the capacity of the boat to see how it influences the number
of passengers the boat is able to hold. Students
graph their results on a two-coordinate graph.

**Word
Bank:
**

Capacity—the
greatest amount of fluid a container can hold |

**Study
Questions:
**

What variable might affect the number of passengers (pennies) a paper-cup can hold? |

Is there a relationship between the capacity of lifeboats and the number of passengers they hold? |

How can you use a two-coordinate graph to predict the number of passengers a new boat would hold? |

Students continue to identify and control variables in an
experiment with planes. They
construct planes and measure the distance it will travel on a fishing line.
Then they chose one variable to change. They change their variable in
increments and record their results. Then
they graph their results and come up with a written conclusion for their
experiment.

**Word
Bank:
**

System—a
set of objects that work together |

**Study
Questions:
**

Why is your plane and flight line a system? | |

What variables had an effect on the FOSS planes? | |

What do we call the two variables we graph on a two-coordinate graph? | |

What is the manipulated variable and which axis is it graphed on? | |

What is the responding variable and which axis is it graphed on? |

Students design their own experiment with a catapult system
based on what they have learned about controlled experiments.

**Study
Questions:
**

Describe the flipper system. Why is it called a system? | |

What variables might affect the distance a ball will fly? | |

What is the relationship between the mass of a foil ball and the distance it flies? | |

Why do scientists conduct multiple trials of the same variable? |