Suppose a stick is struck against a frying pan in vacuum. Will the frying pan vibrate? Will we be able to hear the sound? Explain.

Yes, the frying pan will vibrate. No we will not be able to hear the sound because:

⇒ The vibrations need a medium to travel.

⇒ In vacuum, sound cannot travel and there is no medium by which vibrations (sound) can produced.

⇒ Thus, we will not be able to hear the sound.