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Can you draw it?. 2 people per group Person A=reporter Person B=artists Reporters, open the black folder and look at the picture . And describe what you see to artists. Artists, draw what reporters are describing. Rules. Artists cannot look at the picture in the folder
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Can you draw it? • 2 people per group • Person A=reporter • Person B=artists • Reporters, open the black folder and look at the picture . And describe what you see to artists. Artists, draw what reporters are describing.
Rules • Artists cannot look at the picture in the folder • Reporters cannot comment on artist’s drawing and artist cannot ask how they are doing. Start!
What is Wave? • a wiggle in both space and time • wave extends from one place to another. • source of all waves is something that is vibrating. Waves are propagations of vibrations throughout space.
Crest • point on the medium that exhibits the maximum amount of positive or upward displacement from the rest position
Trough • point on the medium that exhibits the maximum amount of negative or downward displacement from the rest position
Amplitude • maximum amount of displacement of a particle on the medium from its rest position • =distance from rest to crest
Wavelength • distance from any point on a wave to the same point on the next cycle of the wave • distance from the peak of one wave to the peak on the next wave • Unit?
Frequency • how often the particles of the medium vibrate when a wave passes through the medium • =how many waves per second?
Summary Speed=wavelength x frequency
Try it on your own! • What is the v if λ= 8 m and ƒ = 20 Hz? • What is the λ if v = 50 m/s and ƒ = 25 Hz? • What is the ƒ if v = 50 m/s and λ= 10 m?
What is Electromagnetic Spectrum? • Scientists have found that many types of wave can be arranged together like the notes on a piano keyboard, to form a scale • Sound waves are vibration of air particles • Electromagnetic waves are vibrations of magnetic and electric fields • Speed of all these waves are 3x10^8
Cont. • Fill the blanks of the spectrum. • What happens to frequency as wavelength decreases? • What happens to wavelength as frequency decreases? • What happens to energy when frequency increases? • http://www.bbc.co.uk/schools/gcsebitesize/science/21c_pre_2011/radiation/electromagneticradiationact.shtml