Wave Interactions and Behaviors

Wave Behaviors Transmission: Occurs when waves pass through a given point or medium. example: Sound waves transmitted thru solids, liquids and gases. Radio waves are transmitted through one electron through another. Light waves are transmitted – 3 ways light and matter can pass through material. A. Transparent material: Only a small amount of light is reflected or absorbed (may be clear or colored material such as filters, windows).

B. Opaque material: allows no light waves to be transmitted through them. C. Translucent materials: Transmit some light, but cause it to be scattered so no clear image is seen.

Wave Behaviors Absorption- occurs when the energy is not transferred through or reflected by the given medium Disappearance of an electromagnetic wave into a medium. Opposite of reflection We see colors because of the selective absorption of visible light. Objects absorb certain wavelengths and we see what is leftover. The colors we see depend on the wavelength absorbed.

Absorption The apple absorbs all wavelengths except red. Yellow Green Red Blue Red Orange Violet The apple absorbs all wavelengths except red. The apple reflects mostly red. Therefore, it looks like red. Essay question on test!!!

Absorption A material that absorbs all wavelengths of visible light will appear black. In contrast, a material that reflects all wavelengths will appear white. Objects or substances that absorb any wavelength of EM radiation become warmer and convert the absorbed energy to infrared radiation. (GREENHOUSE EFFECT)

Wave Behaviors A. Reflection– bouncing back of a wave as it meets a boundary or surface (pg. - Examples: Echoes, Looking in a mirror

Wave Behaviors B. Refraction– bending of waves as they pass from one medium to another (pg.

Wave Behaviors C. Diffraction– bending of waves around an edge (Pg.

Wave Interactions D. Interferance – combination of 2 or more waves  usually produces one wave (bigger if in phase) (smaller if out of phase)

Wave Interactions Constructive interference – when waves combine to create a bigger wave sum of the amplitudes of the waves Examples: Pg. /

/ Wave Interactions 2. Destructive interference – when waves combine to form a smaller or no wave  some may completely cancel out  difference between the amplitudes of the waves - Example: Pg. /

Wave Interactions E. Wave speed depends on the medium ex. Sound  moves fastest through solids  moves moderately fast through liquids  moves slowest through air/gases (340 m/s) - due to movement of molecules in the medium

Wave Interactions F. Light travels at a constant speed 3x 108 m/s = 300,000,000 m/s (186,000 miles/sec.)