An electric bell is placed inside an airtight glass jar connected to a vacuum pump. As air is continuously…
An electric bell is placed inside an airtight glass jar connected to a vacuum pump. As air is continuously pumped out while the bell rings, what will a person standing outside observe?
The hammer stops striking the metal gong
The sound becomes much louder due to lack of air resistance
The ringing sound grows fainter and eventually becomes silent
The pitch of the ringing sound doubles
Solution
As air is removed, fewer air molecules are present to transmit vibrations, causing the sound to fade away until silence is reached in a full vacuum.