Product Overview
Demonstrates that sound waves need material medium for propagation and cannot travel through vacuum. As the air is pumped out of the sealed bell jar, the sound from the bell gradually fades, then dies.
The demo includes a higher quality acrylic bell jar with silicone rubber sealed metal base plate and a battery-operated electric bell. Quick-fit valve on top of bell jar accepts standard PU tubing (a length of tubing is provided). Electric bell operates on 2 AA batteries and can be suspended from the hook inside the bell jar. Bell jar is 190 mm in diameter and 180 mm high. For use with a vacuum pump. Bell may be removed for other vacuum experiments, e.g. with the baroscope. Batteries are not included.
