Post by toweringniceguy on May 3, 2007 14:41:32 GMT 10
Discovering Sound Waves
Materials required:
A shoe box
Elastic bands - of different widths, large enough to go around the shoe box
A sheet of cardboard
Cello tape
Procedure:
Take the lid off the shoe box. Using some cardboard and cello tape, strengthen the sides and bottom of the box so that the bands don't cut through it.
Fix the elastic bands of different widths around it.
Using your finger, pluck each elastic band in turn.
Ask the child to observe the vibrations of the elastic bands and the sounds made by them.
Shift focus to one particular elastic band. Stretch it with your finger and then pluck it. Note the vibrations and the sound. Release it back to its normal position, and pluck it again. Ask the child if they noticed a difference in the behaviour of the stretched and relaxed band when plucked. Ask the child to experiment with the plucking.
Re-arrange the bands according to the quality of sound emitted - deepest to shrillest or vice versa. Explain the dynamics of sound waves.
Conclusion:
Elastic bands with broader widths will vibrate slower, producing a deeper sound. Thin elastic bands vibrate higher, with a higher frequency, producing sound waves that are shrill.
Explain the effect of stretching on the behaviour of the elastic band - in increasing the length and decreasing the bass quality of the sound it emits.
This experiment explains the visual and auditory behaviour of sound waves and the effect of dimension on the vibrating strings.
Materials required:
A shoe box
Elastic bands - of different widths, large enough to go around the shoe box
A sheet of cardboard
Cello tape
Procedure:
Take the lid off the shoe box. Using some cardboard and cello tape, strengthen the sides and bottom of the box so that the bands don't cut through it.
Fix the elastic bands of different widths around it.
Using your finger, pluck each elastic band in turn.
Ask the child to observe the vibrations of the elastic bands and the sounds made by them.
Shift focus to one particular elastic band. Stretch it with your finger and then pluck it. Note the vibrations and the sound. Release it back to its normal position, and pluck it again. Ask the child if they noticed a difference in the behaviour of the stretched and relaxed band when plucked. Ask the child to experiment with the plucking.
Re-arrange the bands according to the quality of sound emitted - deepest to shrillest or vice versa. Explain the dynamics of sound waves.
Conclusion:
Elastic bands with broader widths will vibrate slower, producing a deeper sound. Thin elastic bands vibrate higher, with a higher frequency, producing sound waves that are shrill.
Explain the effect of stretching on the behaviour of the elastic band - in increasing the length and decreasing the bass quality of the sound it emits.
This experiment explains the visual and auditory behaviour of sound waves and the effect of dimension on the vibrating strings.
Chand meri zameen phool mera watan