WAVES!

DOPPLER EFFECT is a variation in observed frequency when there is relative motion between a source and an observer. Exampes: the pitch of the sound changing. The closer you are to the sound, the higher the pitch will be. The farther away you are, the lower the pitch will be. It's same with color. The farther away you are the dimmer the light is, and the closer you ar, the brighter it will be. The stars shifted towards us is blue while the stars shifted away from us is red is an example of the Doppler Effect.

Interference occurs when two or more waves pass simultaneously through a region. (look at picture A & B about waves interference) waves interference results in a new wave pattern. examples: boat waves, sound waves. Interferences produces beats which is like the spokey or "shuddery" noise when mr. wirth hit those two tone forks. LAW OF SUPERPOSITION- when waves overlap each other. the resultant displacement is the algebraic sum of the individual displacements of each wave. annull = cancel out CONSTRUCTIVE INTERFERENCE- occurs wehn we have two waves arriving at the same point are vibrating in the same direction (in phase). THe two waves are added together to form a bigger. PEAK + PEAK = BIG PEAK & TROUGH + TROUGH = BIG TROUGH

MAXIMUM CONSTRUCTIVE INTERFERNECE- occurs when the phase difference is zero degrees (in phase).
DESTRUCTIVE INTERFERENCE- occurs when 2 waves arriving at the same point are vibrating in opposite directions (out of phase) . waves cancel one another out. PEAK + TROUGH= ZERO.
MAXIMUM DESTRUCTIVE INTERFERENCE- occurs when the phase difference is 180 degrees and its "out of phase".
look at picture for constructive and destructive interference
PATH DIFFERENCE- is the interference between 2 waves of ten occurs due to a difference in length of the path that 2 waves travel.