Waves/ sound test

What is the formula for period?

T=t/n

Period=time/number of cycles

What unit do you use for period?

Seconds

What is the formula for frequency?

f=n/t

frequency= number of cycles/time

What is frequency measured in?

Hertz

Period and frequency are _____

inverse of one another

F=5

T=1/5

What is a transverse wave?

a wave in which the particles move perpendicular to the direction the wave is traveling.(left to right while traveling up and down)

Give an example of a transverse wave

Waves on a beach, Waves on a string

What is a longitudinall wave?

particles move parallel to the direction of the wave(side to side while traveling side to side, moving and compressing in the same direction

What is an example of a longitudinal wave?

Sound waves, slinky

What is velocity measured in?

meters/second

What is wavelength measured in?

meters

What does this mean?

λ

Wavelength

What is the formula for wave velocity if given period?

V=λ/T

What is the formula for wave velocity when given frequency?

V=(λ)x(f)

What is sound?

a type of mechanical wave that results from the vibration of particles in a medium.

Sound requires a _______

medium. It can not propagate in a vaccum(alarm clock video)

Can the speed of sound change?

Yes, it is faster in solids but slower in gases

Why is the speed of sound faster in solids

The molecules are more dense, and speed of sound is slower in gasses bc molecules are spread out

What is the formula for speed

s=d/t

speed=distance/time

What is loudness

how perceived the strength is by the human ear. Larger amplitude= louder sound

What is intensity

the measurement of the power of sound per unit area. its a measurable quantity.

Intensity is ________ to the square distance

inversly proportional.

if one goes up, the other will go down at the same rate

What is the unit used to measure relative intensity

decibels, dB

How many decibels is a normal conversation

60dB

How many dB’s are rustling leaves?

20

How many dB’s is a jet engine

140dB(painfully loud)

What is the Doppler effect?

The change in the frequency or wavelength of a wave as observed by someone moving relative to the sound of the wave.

If the source and observer are moving toward each other, the observed frequency

will increase(higher pitch, louder)

If the source and observer are moving away from each other, the observed frequency

will decrease(lower pitch, quieter)

What is a wave

a vibration or disturbance in space

What do waves need in order for it to pass through?

a medium

_____ types of waves transfer energy

all waves

Define the following term:  wave length

distance from crest to crest 

note: it doesn’t have to be from crest to crest, just the exact point. 

point to point

Define the following term: crest

the highest point the medium rises to

Define the following term: trough

lowest point the medium falls to

Define the following term: period 

time it takes for one full cycle

a wave must have 2 things:

an up and a down

Define the following term:  frequency

amount of cycles that can occur in one second

Define the following term: amplitude

maximum displacement by a point on a wave