Sound is energy that moves back and forth through the air in the form of vibrations. These vibrations spread outward as waves, like the ripples caused by a stone when it is dropped into rather still water.
The first experiment demonstrates the existence and energy of sound waves. Channeling the sound inside a tube concentrates the waves in the direction of the tube. By channeling sound toward a candle, you can use the energy to blow out the flame.
The second experiment is all about the strength of sound waves. It shows that sounds get quieter if their waves are allowed to spread out. Scientists say that loud sounds have large amplitudes (variations of range).
In the final project, you can investigate pitch, or the range of sounds, by making a set of panpipes. Low sounds consist of a small number of vibrations every second. Musicians describe these sounds as having "low pitch" but scientists report the sounds as "low frequency." The panpipes show that pitch depends on the length of each pipe.
Plastic wrap, tube of card, rubber band, candle, matches.
You will hear the sound coming out of the tube. It consists of pressure waves in the air. The tube concentrates the sound waves toward the candle flame and puts it out.
Ticking watch, tube 2 x 36in long.
Scissors, wide drinking straws, nonhardening modeling material, card, tape.