Hobbies And Interests
Resonance
Organs and flutes are examples of instruments that resonate. You can learn about the principle of resonation by studying how air plays upon the pitch of a note in an enclosed space. Fill a glass one-third full with water. Purse your upper lip and blow over the opening of the bottle. A note will be created. Use varying amounts of water in the bottle to get different notes. This demonstrates the change of notes over an enclosed space that happens with instruments.
Musical Scale
The musical scale experiment is a way to learn that you don't need an instrument to play the musical scale. It involves using drinking straws to create different pitches. It is easy and just takes a few minutes. Flatten 2 cm of one end of a drinking straw. Make small, angular cuts on each side of it. Put the flattened end of the straw into your mouth and lightly blow. The experiment can be conducted using different lengths of straws to make different notes.
Tone
This experiment shows how tone is changed with the fluid level in a wine glass. Hold a wine glass at its base, wet a finger and move it in a circle around the rim of the glass. The glass will vibrate a particular frequency. This is called the resonate frequency and it can be changed by varying the amounts of liquid in the glass.
Playing Back Sound
This experiment plays back sound from records and uses simple materials from around the house. Use a can opener and remove both ends of a tin can and wrap a piece of aluminum foil over one end of the can. Make sure the foil stays on by using a rubber band at the edges where the foil meets the rim of the can. Tape a sewing needle over the foil so that one end of the needle sticks out over the rim of the can. Place the needle attached to the can on a groove of a record spinning at 33 rpm. The foil of the tin can acts as a diaphram and vibrates sound. While this experiment works to play back sound, it will also damage the record.