WavesStudy Guide • •
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Wavestravel and transfer energy from one point to another. There are two types of waves: o Mechanical o Electromagnetic Mechanical waves are: o Sound waves o Seismic waves Examples: P-waves and S-waves o Water waves Tsunamis or beach waves of all sizes. The 3 mechanical waves must have a medium to travel through or transfer energy. A medium is any thing that is made of matter and in the following three states: o Solid, Liquid, and Gas Transverse waves:
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The amplitude of the wave depends on the amount of energy the wave has. Frequency is the number of waves in a time period.
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Compressional wave:
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While completing one of our labs using a slinky, we push energy down the slinky. This was an example of: o P-waves o Compressional Waves o Longitudinal waves When humans hold hands and move their arms in a wave like motion this is called a human wave model. This models: o Transverse waves o S-waves o Mechanical Waves Electromagnetic waves do not require a medium and travel through matter and space without causing a disturbance. Examples: o Radio waves o Microwaves o Infrared waves o Visible light o Ultraviolet light o X-rays o Gamma Rays Electromagnetic spectrum o Shorter waves lengths create higher energy o Longer wave lengths create less energy o More waves in a given amount of time or higher frequency creates higher energy. o Fewer waves in a given amount of time or lower frequency creates lower energy. Look at the chart below showing the electromagnetic spectrum. Notice how radio waves have a longer wavelength and a lower frequency so radio waves have low energy. Gamma rays have a shorter wavelength and a higher frequency so they gamma rays have a lot of energy.
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Astronomers use light years to measure long distances in space. Light travels very fast and objects in space are very far away. Light years measure distance. Examples of when astronomers would use light years to measure distance: o Distance between stars o Distance between galaxies Origins of the Universe o The Oscillating Universe is one theory stating that the universe is continually expanding and contracting. The Big Bang Theory included black holes in its explanation of the formation of the universe. o Scientist that believe in the big bang theory believe the universe was once more denser and hotter. o The best evidence scientist have to support the big bang theory is the red shift of light from stars.