Sunday, May 15, 2011
Tuesday, May 3, 2011
Sound- pressure variations in matter, like water and air. Does not travel through a vacuum. Radio waves are electromagnetic waves that do trave through a vacuum. When you tune on te radio, you hear the music and sounds because the radio station has a transmitter that converts the sound waves into electromagnetic waves. A transmitter is an electornic device that with the use of an antenna, produces radio waves. The electromagnetic waves are then encoded onto an electromagnetic wave in radio frequency range. AM radio range is 500-1600 kHz and for FM radio, it's 86-107 kHz. Radio electromagnetic waves are important because they travel through large spaces without being absorbed. Radios receive radio information, decode the information and uses speakers to change it into a sound wave.