Wave Interactions

I. Reflection A. Definition: bouncing back of waves as it meets the surface boundary 1. Waves come back inverted (upside down) at a fixed boundary

2. Waves come back the same at a free/soft boundary.

II. Diffraction A. Definition: the bending of a wave as it passes an edge or an opening

1. as a wave pass the edge of an object or through an opening, they spread out  bend around an object or opening

III. Refraction A. Definition: the bending of waves as they pass from medium to another Example: pencil in water  Looks broken

B. Each time a wave enters a new medium it will bend slightly

IV. Wave Interference A. The combination of two or more waves that exist in the same place at the same time

1. Constructive Interference: When small waves combine to form a bigger wave

2. Destructive Interference: When waves combine to form a wave smaller than the largest original wave

The Doppler Effect: an observed change in the frequency of a wave when the source or observer is moving A. Pitch:determined by frequency of sound waves

A. Pitch:determined by frequency of sound waves 1. Higher frequency higher pitch 2. Lower frequency lower pitch

B. If an object is standing still the frequency will remain constant

If the object is moving, the frequency will change 1. As the object moves towards you, the waves are squished together (increasing frequency)  higher pitch

As the object is moving away from you, the waves are spread out (lowering frequency) lower pitch

VI: Polarization of light waves A. Most of the light we see produce vibrations in many random directions (not polarized) B. Polarized light travels in transverse waves: up and down or side to side