3N3
is unpredictable
US. TALK.
BYEBYE.
Cheera Hazhmirra
Jermaine
Jingsheng
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Teacher-in-charge: Mr chio Students: Adlin, Diyanah, Elisa, Grace, Jermaine, Jingsheng, Pauline, Qianwei, Saiful, Tabatha, Vinis, Wende, Zongxian, Wednesday, April 14, 2010
10:45 PM
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A wave is a disturbance that propagates through space and time, usually with transference of energy. A mechanical wave is a wave that propagates or travels through a medium due to the restoring forces it produces upon deformation. For example, when a sound wave is traveling through the air, air molecules slam into their neighbors, which pushes their neighbors into their neighbors (and so on); but when air molecules collide with their neighbors, they also bounce away from them back in the direction they came from. These collisions provide a restoring force that keeps the molecules from actually traveling with the wave. Waves travel and transfer energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass transport; they consist instead of oscillations or vibrations around almost fixed locations. In the picture of water waves, if we imagine a cork on the water, it would bob up and down staying in about the same place, although the wave itself is moving outward. When we say that a wave carries energy but not mass, we are referring to this fact that even as the wave travels outward from the center (carrying energy of motion), the medium itself does not flow with it. There are also waves capable of traveling through a vacuum, including electromagnetic radiation. Ultraviolet radiation, infrared radiation, gamma rays, X-rays, and radio waves are examples of these types of waves. They consist of period oscillations in electrical and magnetic properties that grow, reach a peak, diminish, go to zero, and then continue these changes in a periodic fashion. As well, it is believed that gravitational waves travel through space; gravitational waves have never been directly detected but are believed to exist.[by Muhd Syafiq 3N3] |