# Energy

Interactive Notes Presentation Packet (Chapter 9)
1. The behavior of waves   a. Reflection i. Occurs when a wave strikes and object & bounces off of it. ii. All types of waves - including light, sound and water, can be reflected. iii. echoes are a result of reflecting sound waves.
2. The law of reflection the angle by incidence beem is always equal to the angle of reflecton. the angle formed by the incidence beam is labeled "i" and the angle formed by the reflected beam is labeled "r". All waves obey the law of reflection.
3. Refractions can cause optical illusions. See the image with the pencils in water. This is because the light waver coming from the immersed straw are refracted and your brain perceives the object in a straight line.
4. diffraction and wavelength when an obsta le is roughly the same size as or smaller than the wavelength of wave, the wave bends around it. when and obstaclwe is larger than the wavelength almost no diffraction occurs.
5. interference the process of two or maor waves overlapping and combining to   form a new wave. a new wave will only exist while the two original waves continue to overlap. two waves can combine through either constructive interfence or destructive interference.
6. constructive inter freence- waves added together .the crest of two or more transverse waves arrive.
7. destructive interference- waves subtract each other. the waves subtract from eacther as they overlap. the crests on one transverse wave meets the troughs of another transverse wave.
8. standing wave(definition): Special type of wave pattern that forms when waves equal in wavelength and amplitude but traveling in opposite directions continuously interfere with each other. standing waces hace nodes, which was locations where the interfering waves always cancel. if you attaach one end of a rope to a fixed point and wace the rope, a standing wave will occur. standing waves occur in music, such as when a violin plas a chord with a bow and it vibrates...