1	WAVES and ENERGY
2	Let’s Start with a Demo
3	"STOP!!!" STOP!!! What do waves transfer? Answer: Energy!!!
4	"What is a wave?" What is a wave? Waves transport energy from one place to another Waves are disturbances or variations that travel and transport energy They transport ENERGY, NOT the medium or matter they travel through. Tasks… List as many examples as you can of waves… What do waves transport?
5	"There are 2 main types..." There are 2 main types of Waves Longitudinal Transverse
6	"Again," Again, there are two main types of waves: Transverse and Longitudinal Transverse waves = perpendicular disturbance to direction of wave (like waves through a rope) Longitudinal waves = parallel disturbance to direction of wave (like pushing on a slinky)
7	"Transverse:" Transverse: the disturbance in transverse waves is perpendicular to the direction of the wave
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9	"Transverse:" Transverse: medium/molecules move perpendicular to the direction the wave travels
10	"Longitudinal:" Longitudinal: medium/molecules move parallel to direction the wave travels Compression: closely packed molecules/medium Rarefaction: widely-spaced molecules/medium
11	"Longitudinal (also known as..." Longitudinal (also known as compression waves) the disturbance is parallel to direction of the wave for compression waves
12	"Examples of longitudinal waves are" Examples of longitudinal waves are: sound waves and P-type earthquake waves
13	"Longitudinal waves travel faster through..." Longitudinal waves travel faster through more dense materials. For example, sound waves travel faster under water than they do through air…
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15	STOP!!! Let’s Review Turn to your partner and discuss the following questions – be prepared to share! What is a wave, what do they travel through, & what do they transfer? What are the 2 types of waves? What are the 2 classifications of a wave (in terms of the direction the particles travel as the wave passes through)
16	Practice Time Turn to page 462 in the class set of Science Spectrum books, and answer the practice problems 1-5.
17	Wave anatomy (the parts of a wave) Wave Crest The highest point of a wave Wave trough The lowest point of a wave. Wavelength Distance from any point on one wave to the identical point on the next wave (crest to crest; trough to trough; beginning to beginning) Height Distance from crest to trough Amplitude Distance from centerline of wave to top of crest or bottom of trough
18	"To figure out the amplitude..." To figure out the amplitude of a wave, find where the wave is at rest (usually 0). The distance from rest to the crest or trough is the amplitude. To figure out the wavelength, find the same point at two consecutive waves. The distance between the two points is the wavelength.
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20	Wave math Cycle The movement from some point, to another point and back again Frequency: number of wave crests/trough that pass a point in a given period of time after the first/leading trough/crest (usually cycles/sec = Hz) T = 1/f or F = 1/T Period: the time required for one full wavelength to pass a given point Wave Equation The wave equation tells us that the relationship between the velocity (speed) of a wave and its frequency is: v=lf
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23	The Doppler Effect
24	STOP!!! Let’s Review Turn to your partner and discuss the following questions – be prepared to share! What are the parts of a wave? What is the difference between the frequency and period of a wave? What is the Doppler Effect?
25	Practice Time Turn to page 471 and answer questions 1-9. Answer your questions completely! Start by writing the equation and then solving for the answer – I want to see your work!