Physics of Sound Investigation 2, Part 3

1. Tension and Pitch Physics of SoundInvestigation 2, Part 3

2. Materials • Student sheet no. 11 called The Minigutbucket • Student sheet no. 12 called The FOSS-ulele • Large plastic bags • Small nail • Scissors • Metric tape • 2 Plastic cups • 50 cm string • 3 large paper clips • Pencil • 250 cm string • Masking tape

3. Minigutbucket (for teacher) • Insert string through hole in plastic cup. • Tie a knot at the end of the string. • Tie the opposite end of the string around a chair or table leg.

4. FOSS-ulele (for teacher) • Place a plastic cup upside down on a table. • Tie one end of the string to a table leg. • Feed the string through the plastic cup. • Tie a pencil to the other end of the string.

5. Introduction • What is tension? (A force pulling on an object in opposite directions.) • How does tension affect pitch? • Will find out by exploring 2 instruments.

6. Instruments • 5 minutes to explore • Minigutbucket • Demonstrate how attaches to a table leg. • Show how to apply tension to the string by pulling gently but firmly on the cup. • FOSS-ulele • Demonstrate how to use the paper clip to affix the string to a table let, bring the string across the cup on top of the table, and use the pencil like a handle to apply tension to the string.

9. Student sheets • Distribute • Read instructions • Record observations • Describe the methods used to change the pitch. • How did you change the tension of the strings on the 2 instruments? • What happened to the pitch of the sound produced by the string as you changed the tension o the strings?

10. Review • Tension – force applied to an object trying to pull it apart • What happens t the pitch when the tension on a sound source changes? (The greater the tension on a sound source, the higher the pitch.) • Science Story – Scoping out Sound

11. The End!!!