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Wave Behavior. Unit 7 –Lecture 3. Clarity. Substances have varying levels of clarity – transparent materials allow waves to pass through with minimum or no distortion. Clarity. Substances have varying levels of clarity –
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Wave Behavior Unit 7 –Lecture 3
Clarity • Substances have varying levels of clarity – • transparent materials allow waves to pass through with minimum or no distortion
Clarity • Substances have varying levels of clarity – • translucent materials allow waves to pass through them with varying degrees of distortion
Clarity • Substances have varying levels of clarity – • opaque materials do not allow waves to pass through them • waves must be reflected or absorbed
Reflection • occurs when a wave strikes an object and bounces off of it • echos (& echolocation) • image in mirror
Reflection • Law of Reflection • the angle of incidence [input] must equal the angle of reflection [output]
Mirrors • mirrors must be smooth so all the angles line up to make a clear picture in the reflection [plan(e/ar)] Smooth Surface Rough Surface
Mirrors • Concave • “caved in” • light rays, etc., converge in the center • make the image larger or focus energy
Mirrors • Parabolic • Satellite dishes • Lighting the Olympic Torch
Mirrors • Convex • “curved out” • Light rays, etc., spread out from the center • Images look smaller, but cover more area
Refraction • bending of a wave as it moves from one medium to another • the image difference is caused by a change in the speed of the wave
Refraction • “edges” of wave “slow down” in a more dense medium and “speed up” in a less dense medium • bends towards the “normal” in a more dense medium • away from the “normal” in a less dense medium
Refraction • depends on the • type of medium • the angle the wave hits the medium • waves of light move faster through air than through water
Refraction • Law of Refraction
Refraction • Oil & Gasoline Rainbows • because of the different densities of oil, gasoline, water, and air, a rainbow-like refraction can form in puddles near well-traveled parking lots
Refraction • Lenses act to control the refraction of light to focus it in a more desirable manner.
Diffraction • the bending of waves around a barrier • if 1 edge, only one curve • if 2 edges, both will bend the wave
Interference • caused by the passing of two waves through one another • how the waves line up determines how they will interact
Interference • constructive interference – • crests and troughs line up • build on one another • are said to be “in phase”
Interference • destructive interference – • crests and troughs don’t line up • lessen one another • said to be “out of phase” • if they are exactly opposite, they will cancel each other out
Homework • FINISH YOUR WAVES PACKET • We will be going over it on Monday. • complete worksheet on back of notes • study for upcoming test = Weds next week