What does the frequency of a wave represent?
the distance between two consecutive crests
the number of wave cycles that pass through a specific point within a given time period
the distance between the highest and lowest points of a wave the length of wave that pass through a specific point within a given time period

How is it possible for someone to put an ear to a wall and hear someone in the next room?     a.sound waves can travel though solids.    b.the waves travel from room to room via air.    c.there must be some air in the wall so the sound can travel through it.    d.sound waves change to electromagnetic waves and then back again.