Sound: The Highs and Lows of Pitch By Stephanie Nafso SCE 5020-Fall 2011

Research Question How does the large spoon sound compared to the small spoon sound when it is hit with a wooden ruler?

Hypothesis If I strike the large hanging spoon with a wooden ruler, then it will produce a low-pitch sound. If I strike the small hanging spoon with a wooden ruler, then it will produce a high-pitch sound.

INTRODUCTION Sounds are tiny movements of air. Sound travels in waves. As an object vibrates, it moves the air around it. Sound moves through all states of matter. Sound has a property called pitch. Pitch of a sound is its frequency or how slow or fast the vibrations are. High-frequency vibrations move quickly and produce a high pitch sound. Low-frequency vibrations move slowly and produce a low pitch sound. The size of an object (due to the amount of matter) affects its pitch. A large object vibrates more slowly and has a low pitch. A small object vibrates quickly and has a high pitch sound. My science experiment demonstrates the high/low pitch of a spoon that is 4 ½ inches and 8 inches.

Methods Manipulated Variables: 4 ½ stainless steel spoon 8 in stainless steel spoon Dependent Variable: the force at which the spoons are hit Controlled Variable: the length of the string, cups, wooden ruler, frequency meter, and myself

Materials 2-24 inch yarn Myself Frequency meter 7 oz paper cups 12 inch wooden ruler Adult Scissors Push Pin 4 ½ inch stainless steel spoon 8 inch stainless steel spoon 2 Small Sized Paper Clips

Procedure Thread it all the way through. Cut 2 -24 in yarn. Strike the fatter part of the spoon with the wooden ruler. The spoons should hang like this. Use a push pin to punch a small hole at the bottom of the cup. Pull the yarn until the paper clip stops it. While striking the spoons, watch the sound meter for the sound measure. Tie the other end of the yarn to the skinny end of the large spoon. Put the cup to your ear. Tie a paper clip to each piece of yarn. Note the reading in hertz. Thread the yarn though the bottom each cup. Tie the other end of the yarn to the skinny end of the smaller spoon. Let the spoon dangle without touching anything.

Results for the Small Spoon Trial 1 Trial 4 Trial 5 Trial 2 Frequency of a Pitch Hertz (vibrations/sec) Trial 3 Trials

Results for the Big Spoon Trial 1 Trial 4 Trial 5 Frequency of a Pitch Trial 2 Hertz (vibrations/sec) Trial 3 Trials

Comparison of the Results Frequency of a Pitch When the smaller spoon was struck with the wooden ruler, it produced a high pitch, where the frequency or speed of the vibrations move quickly and are measured in hertz. When the bigger spoon was struck with the wooden ruler, it produced a low pitch, where the frequency or speed of the vibrations move slowly and are also measured in hertz. Hertz (vibrations/sec) Trials Comparing the frequencies of the pitch for the small spoon to the big spoon, notice that the frequencies for the small spoon are almost two times more than the frequencies of the big spoon. There are more vibrations per second for the small spoon because its pitch is high. There are less vibrations per second for the big spoon because its pitch is low.

Conclusion My hypothesis was supported, because when I struck the small spoon, my vibrations detector measured the vibrations of the small spoon’s pitch. The sound waves on the screen showed that the small spoon was producing a high-pitch. This was evident because the frequency waves had many more wavelengths passing per second. Then when I struck the big spoon, my vibrations detector measured the vibrations of the big spoon. The sound waves on the screen showed that the big spoon was producing a low-pitch. This was evident because the frequency waves had less Conclusion: High frequency=high pitch Low frequency=low pitch