This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Changing Sounds Sound is a form of energy. For sound to be produced vibrations must be set up by a source. This is done by hitting (drum), blowing (recorder), stroking (sand paper on wood) and electrical (loudspeaker). The vibrations travel through a solid liquid or gas and reach our ears where it can be heard. If the vibrations have a lot of energy then they are loud. If they have little energy then the sound is quiet. Sometimes the vibrations can be seen or felt on the skin. In air, sound travels at 1,160 km per hour, but speeds up in water to 5, 400km per hour. Things which travel faster than sound are called supersonic. The Concorde can travel faster than sound. Dolphins communicate with each other under the sea. The sound can travel for hundreds of miles, much further than in air. Sound travels even more quickly through a solid metal than through the air or water. Standing near a railway line, a humming from the rails can be heard several minutes before a train itself can be heard directly. Sound travels through solids and liquids as well as air. Sound cannot travel through a vacuum. Sound travels at different speeds in different substances. This is because a vacuum....
View Full Document
This note was uploaded on 11/29/2011 for the course PHYS 122 taught by Professor Terry during the Fall '11 term at BYU.
- Fall '11