Question

In the experiment shown, the bell is heard ringing. The air is gradually pumped out of the jar. No change is made to the ringing bell. After a few minutes the bell can no longer be heard. Why is this?

• A. The amplitude of vibration of the bell decreases.
• B. The frequency of vibration of the bell increases.
• C. The sound waves from the bell become transverse.
• D. The sound waves need a medium to travel through.

Answer 1

The correct option is D The sound waves need a medium to travel through.

The sound waves need a medium to travel through.