Chapter 13 wave motion and sound 2. Electromagnetic Waves 电磁波: Such as light, radio and television waves, X rays. These waves require no material medium to exist. Its speed through the vacuum iS299792458m/s Examples: Visible and ultraviolet light, radio and television waves, microwaves x rays and radar wavesChapter 13 Wave Motion and Sound 2. Electromagnetic Waves 电磁波: Such as light, radio and television waves, X rays. These waves require no material medium to exist. Its speed through the vacuum is 299792458m/s. Examples: Visible and ultraviolet light, radio and television waves, microwaves, x rays, and radar waves