Wa-9 Sound in a Vacuum

Aim

To demonstrate that sound cannot be transmitted through a vacuum.

Apparatus

  • Bell Jar
  • Doorbell Ringer Apparatus
  • Rotary Vacuum Pump

Sound in a Vacuum 1 Sound in a Vacuum 2

Sound in Vacuum Setup.

Description

The Doorbell is set ringing under normal atmospheric pressure, and can be heard quite clearly. As the Bell jar is evacuated, the ringing sound will disappear, when a reasonable vacuum is reached.

Video