physics trick

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Anajean Jandayan IV-Socrates Straw Oboes Objectives To make an amusing demonstration of the physics of music. To make a straw sound like an oboe! Materials •straws (need to be straight – cut off the bendy bits if there are any) •scissors Procedure 1. Flatten one end of the straw ~2cm from the end to the tip. 2. Make two cuts in the now flattened end of the straw, to form a triangular tip. 3. Insert the triangular tip of the straw into your mouth and blow hard. You should hear a loud 'buzzing' sound. 4. While blowing on the straw oboe, get a volunteer to cut the straw shorter, ~1cm at a time. With each cut you will hear the pitch of the oboe sound go up. Diagram/Pictures

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This document involves the use of science in magic! It was performed as part of our performance-based exam. The procedures and some pictures were included. :D

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Page 1: Physics Trick

Anajean Jandayan IV-Socrates

Straw OboesObjectives

To make an amusing demonstration of the physics of music. To make a straw sound like an oboe!

Materials•straws (need to be straight – cut off the bendy bits if there are any) •scissors

Procedure1. Flatten one end of the straw ~2cm from the end to the tip. 2. Make two cuts in the now flattened end of the straw, to form a triangular tip. 3. Insert the triangular tip of the straw into your mouth and blow hard. You should hear a loud 'buzzing' sound. 4. While blowing on the straw oboe, get a volunteer to cut the straw shorter, ~1cm at a time. With each cut you will hear the pitch of the oboe sound go up.

Diagram/Pictures

Theory/Principle The flattened triangular tip acts like the reed found in most wind instruments. Blowing on

the reed causes the straw to vibrate. A standing wave pattern is created along the length of the straw, which we hear as sound. As you shorten the straw you shorten the wavelength of the standing wave pattern and therefore increase the pitch of the note.

Unfortunately, unlike an oboe, once you've cut your straw down, you can't make it into a long straw again so playing a tune is almost impossible. You could of course cut a series of straws to different lengths and switch between straws to play your favorite song.