Question 7
Use a 30 cm plastic ruler and a table. Place the ruler perpendicular to the table edge, with 15 cm extending over it. Hold the ruler firmly flat on the table and flick the free end. Listen to its pitch as the reference (control) test. Repeat with extensions of 5 cm, 10 cm, 20 cm and 25 cm, comparing each pitch with the 15 cm reference.
Why did the ruler produce a sound when it was flicked?
Why did the ruler produce a sound when it was flicked?
