waves unit

Period (seconds)

the time for one full cycle

frequency

the number of cycles in one second

time for one swing (pendelum)

period

oscillation

repeated back and forth movement

waves

a disturbance or oscillation (back and forth movement) that transfers energy but not particles through space

transverse waves

particle motion is perpendicular to the direction of the energy moving.

mechanical waves

both transverse and longitudinal waves that require a PHYSICAL medium (air, water..)

electromagnetic

transverse waves that do not require a medium for energy to travel (light)

_______ of the wave is determined by medium only

wave speed

frequency and wave length have a _____ relationship

inverse

wavespeed is a fixed number, so if frequency goes up _____ will change

wave length

interference

when waves meet at a point in space, resulting in an addition of the amplitudes

constructive interference

amplitudes going in same direction that are added together when they meet

destructive interference

amplitudes going in opposite directions will subtract and make a smaller wave. it will cancel if both waves are equal in magnitude

standing waves

continuous constructive and destructive interference of waves

node

total destructive interference. points in a standing wave with no movement

antinode

total constructive interference. points in a standing wave with maximum movement.

for sound waves, frequency of vibrations determine...

pitch. how high or how low it is

for sound waves, amplitude is related to the

energy and loudness.

decibles

logarithmic functions. to go up by 10dB, multiply ur variable by 10

is sound faster in warmer or colder air?

warmer

infrasonic

below 20 Hz

ultrasonic

above 20,000

Beat frequency

the wobble you hear when there are 2 different frequencies. i.e periodic variation in loudness of two sounds played together

resonance

when a driving frequency matches an objects natural frequency and causes a greater amplitude

frequency and pitch are directly related

in the doppler effect, when the car is coming towards you, waves are compressing, making a higher frequency which is making you HEAR a higher pitch. when it goes past you, you are perceiving a lower frequency, so you HEAR a lower pitch.

if an object is faster than the speed of sound in air, the object is

supersonic

the shockwave of pressure behind an object that is supersonic is

sonic boom