Abell is rung. what best describes the density of air around the bell?
a. the air density does not change.
b. the air density increases and then returns to normal levels.
c. the air density decreases and then returns to normal levels.
d. the air density increases and decreases repeatedly before returning to normal.

d.  The air density increases and decreases repeatedly before returning to normal.

Explanation:

when sound wave travel in the air then the air molecules will move to and fro about their mean position due to which sound energy propagate into the medium.

Due to this propagation of sound through the medium the pressure in the medium will go increasing and decreasing in form of rarefaction and compression and given as

so here since pressure is changing from maximum to minimum so here density of medium also changes. So correct answer will be

d.  The air density increases and decreases repeatedly before returning to normal.

gans

explanation:

vestigial organs (like your appendix) are organs that no longer serve a purpose.

explanation:

a fuel engine ( known as a gasoline engine in american english )is an internal combustion engine with spark ignition, designed to run on petrol (gasoline) and similar volatile fuels.