This economical buzzer has several uses in a physical science classroom. One use is to demonstrate fundamental principles of sound. Tie a string to the buzzer. Spin the buzzer over your head and students will clearly hear the Doppler effect as the buzzer's pitch changes. Battery and buzzer are secure so there is no worry of the battery disconnecting. For another demonstration, place the operating buzzer on a foam pad inside a bell jar. Evacuate the air from inside the bell jar with vacuum pump and the sound disappears! Effectively show students that sounds do not exist in the vacuum of space. Foam pad prevents any buzzer vibrations from generating extraneous sound through the vacuum plate. Complete instructions for the two mentioned demonstrations are provided. Buzzer requires a 9-V battery, but is not included. Optional accessories for certain demonstrations include a bell jar, vacuum plate, vacuum pump and vacuum tubing; each sold separately.
Flinn Catalog/Reference Manual Page 714
Flinn Middle School Catalog/Reference Manual Page 465