In this middle school lesson plan developed by our partner, PhET, students use an interactive simulation called Pendulum Lab to design controlled experiments to identify how variables affect the motion of a pendulum.

### Students will:

1. Design experiments to describe how variables affect the motion of a pendulum.
2. Use a photogate timer to determine quantitatively how the period of a pendulum depends on the variables you described.

### Materials:

• Computers or other devices with internet access

### Preparation:

This lesson plan features an interactive simulation titled Pendulum Lab, developed by our award-winning partner PhET through the University of Colorado Boulder. The simulation invites students to to design controlled experiments to identify how variables affect the motion of a pendulum.

Review the Pendulum Lab Simulation Overview to learn about the sim controls, model simplifications, and insights into student thinking.

Preview and play with the Pendulum Lab sim to plan how you will adapt it to your students’ needs.

Build background knowledge or reinforce topics with these BrainPOP movies: Newton's Laws of Motion, Gravity, Work, Isaac Newton, and Forces.

### Lesson Procedure:

1. Show the BrainPOP movie Newton's Laws of Motion to the class.  Discuss what they learned after viewing. Then tell them they will now use a simulation  to design an experiment determining variables that affect the motion of a pendulum.
2. Have students open and play with Pendulum Lab.Challenge them to figure out which variables, such as length, mass, gravity, and angle, affect the motion of a pendulum and write qualitative descriptions for each variable.
3. Now have students design experiments to find the best equation for the relationship for length and period. To do this, instruct them to follow these steps:
• Make a data table with at least 10 points in an Excel spreadsheet.
• Then, make a scatter plot type of chart.
• Describe in your own words what the relationship is.
• If you know how, add a trendline from Excel.
4. Next, students design experiments to find the best equation for the relationship for initial angle and period. To do this, instruct them to follow these steps:
• Make a data table with at least 10 points in an Excel spreadsheet.
• Then, make a scatter plot type of chart.
• Describe in your own words what the relationship is.
• If you know how, add a trendline from Excel.
Filed as:  3-5, 3-5-ETS1-2, 3-5-ETS1-3, 4-PS3-1, 4-PS3-4, 5-PS2-1, 6-8, 9-12, CCSS.ELA-Literacy.RI.4.1, CCSS.ELA-Literacy.RI.4.3