## Silly Putty 1: Brittle, Ductile, AND Elastic

#### Objectives:

This activity extends student understanding of the deformation a rock undergoes as a result of stress, plus several factors that contribute to the behavior. Students work in pairs to explore deformation using Silly Putty. The student worksheet ties the deformation to the concepts of faulting (earthquakes) and folding, and ultimately concludes with an opportunity for students to design their own deformation experiment. Inclusion of the “Marble Tongs” activity is not required, but reinforces the concept that rock can be elastic.

This activity is designed to take 15 minutes as a demonstrated inquiry, or 45 minutes as a structured inquiry.

#### Keypoints:

Students will be able to:

• Demonstrate the three types of stress using Silly Putty.
• Define strain in a written paragraph.
• Demonstrate brittle, ductile and elastic deformation using common objects.
• Demonstrate that rocks can be elastic with Marble Tongs.
• Describe the cause of an earthquake using the terms stress, strain, elastic rebound, fracture, potential energy, kinetic energy.

Level: Novice

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