Waves are everywhere. Most of the information that we receive comes to us in the form of waves. You rely on waves to bring you music and TV. You can cook with waves, talk to others and see things all because of waves. Waves transfer energy in different forms, some are very useful, while others can be deadly.
A Tsunamis or tidal wave is a very large water wave that has been produced by some kind of seismic phenomona. These waves can move at speeds of 500 km/h and have a period of 60 minutes. They can move across the ocean very quickly and cause incrediable damage to coastal regions.
Animals use wave motion to propel themselves through there surroundings. Eels and snakes use transverse body waves to push against the water or ground to help them move. Earth worms however, use longitudinal waves for propulsion. Others, like certain one-celled animals use flagella in a whiplike wave motion to move about their world.
Shock waves created out by a lighting may cause a sonic boom. Sonic booms can also be produced by aircraft flying at speeds greater than the speed of sound in air. Because of this the Concord aircraft has been banned from flying over inland portions of the United States.
For Sound Waves:
Since sound can not travel in a vacuum, acoustic engineers can design soundproof barriers or rooms. If you remove the air between two walls you will be able to greatly reduce the amount of sound that is transmitted. You can also place sound absorbing materials, like the insulation in your home, between the walls to cut down on the transmition of sound waves.
Compared to light, sound waves travel relatively slowly. Because of this slowness in the movement of sound waves, your brain is able to help you locate the source of a sound. There is a measurable difference in the time it takes the sound to reach both of your ears. From this you can tell where the source is located.
You can use sound to measure distances. Using the equation d=(techo x vsound)/2, where techo is the time required for an echo and vsound is the velocity of sound, mountain climbers can deteremine the width of a valley, while exploration geophysicists can determine the depth of an oil well.
Similarly, SONAR (sound navigation and ranging) is used in detecting objects underwater based on an acoustic echo. The time difference between the signal being sent and received indicates the distance to the object. Today the fishinig industry both commercial and recreational use sonar to locate schools of fish. This has also been used in locating ships, and their cargo, when they have sunk.
The massive compression waves produced by an earthquake are similar to sound waves. By using a process of triangulation, and knowing how fast these waves travel in the earths crust, sismologist are able to deteremine the epicenter of an earthquake.
Compression waves travel faster in solids than through air. Because of this it is possible to detect the tremors produced by an explosion before you hear the sound of an explosion off in the distance.
Ultrasonic or high-frequency sound waves have been used to clean jewelry and teeth, help animals communicate and aid physicians in making observations of internal organs. It has also been used to remove kidney and gallstones by breaking the stones. Burglar alarms can use the doppler effect to detect motion in a room.
The quality of sound coming from a musical instrument depends upon the number of harmonic frequencies produced and their relative intensities. Wind instruments rely on resonance while stringed instruments make use of the law of strings.
Eavesdropping or "listening without being seen", makes use of the fact that sound can diffract or bend as it travels through your house. Light waves, however do not bend in this manner. Therefore, you can hear around corners that you can not see around.
If you have a two-speaker P.A. system, interference patterns can be created. This is an area where nodal lines and antinodal lines are produced. In an area of nodal lines the sound will be softer whereas in an area of antinodal lines the sound will be louder.
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