Section 3: Behavior of Waves Waves, Chapter 11 Section 3: Behavior of Waves

Reflection occurs when a wave strikes an object and bounces off of it All types of waves can be reflected Law of Reflection The angle of incidence of a wave is always equal to the angle of reflection.

Law of Reflection Normal- an imaginary line perpendicular to a reflective surface Angle of incidence- the angle formed by the wave striking the surface and the normal Angle of reflection- the angle formed by the reflected wave and the normal

Refraction the bending of a wave caused by a change in its speed as it moves from one medium to another The greater the change in speed, the more the wave bends When a wave passes into a material that slows it down, the wave is bent toward the normal When a wave passes into a material that speeds it up, the wave is bent away from the normal http://www.mysundial.ca/tsp/refraction_of_light.html

Diffraction an object causes a wave to change direction and bend around it If the obstacle is smaller than the wavelength, the wave diffracts a lot If the obstacle is much larger than the wavelength, the wave does not diffract much The larger the obstacle is compared to the wavelength, the less the waves will diffract http://piru.alexandria.ucsb.edu/~tierney/TRS/lecture10.htm

Diffraction Links/Animations http://www.acoustics.salford.ac.uk/feschools/waves/diffract.htm http://www.acoustics.salford.ac.uk/feschools/waves/diffract3.htm http://homepage.univie.ac.at/Franz.Embacher/KinderUni2005/waves.gif

Interference the ability of two or more waves to combine to form a new wave Waves pass right through each other and continue in the original direction New waves exist only while the two original waves continue to overlap http://faculty.virginia.edu/consciousness/new_page_7.htm

Interference: Two Types Constructive Interference waves add together and become “phased” http://astro-canada.ca/_en/a2313.html

Interference: Two Types Destructive Interference waves subtract from each other http://astro-canada.ca/_en/a2313.html

Standing Wave a wave pattern that stays in one place Form when waves of equal wavelength and amplitude that are traveling in opposite directions continuously interfere with each other Nodes- the places where two waves always cancel each other http://www1.union.edu/newmanj/lasers/Light%20as%20a%20Wave/light_as_a_wave.htm http://www.youtube.com/watch?v=NpEevfOU4Z8

Resonance the ability of an object to vibrate by absorbing energy at its natural frequency An opera singer hits a high note and breaks glass Nikola Tesla