EDITING - PLEASE DO NOT ANSWER YET - THANKS.

Suppose I have a sealed glass vessel of radius r that is evacuated. I smash it.

How fast will air molecules move into the vacuum. Will they move at the speed of sound (in air)?

It seems to me that the speed of sound as a wave is not necessarily the same as the mean velocity of the air molecules themselves. Can someone enlighten me? Thanks.

Note

I'm not certain how well-defined my question is. Suggestions for improvement would be appreciated.

Suppose I have a sealed glass cylindrical vessel of radius r and length l that is evacuated. I smash one end.

How long will it take for air to (a) reach the end of the cylinder (b) fill the vacuum and equalise the pressure? Will the air molecules move at the speed of sound?

It seems to me that the speed of sound as a wave is not necessarily the same as the mean velocity of the air molecules themselves. Can someone enlighten me? Thanks.

Note

I'm not certain how well-defined my question is. Suggestions for improvement would be appreciated.