Ruler Guitar Pitch

1. Ruler Guitar Pitch Materials: Plastic ruler; table edge What you do: Hold different lengths of ruler over the edge and pluck. What students see: Shorter lengths vibrate faster and sound higher. Question: What changes when less ruler sticks out? 2. Coat-Hanger Bell Through String Materials: Metal coat hanger; two strings What you do: Tie strings to hanger, place fingers near ears, and gently tap hanger. What students see: A quiet tap sounds like a huge bell through the strings. Question: Why is it louder through the string? 3. Rice Jumps on a Sound Membrane Materials: Bowl; stretched plastic wrap; dry rice; speaker What you do: Place rice on taut wrap and make sound nearby. What students see: Rice jumps when the membrane vibrates. Question: Can we see sound moving something?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: What changes when less ruler sticks out? Question: Why is it louder through the string? Question: Can we see sound moving something?