Sound and Light- Units 1, 2, & 3
Terms in this set (38)
What is a mechanical wave?
a wave that requires a medium through which to travel
How does a transverse wave move?
the particles move perpendicularly to the direction the wave travels
How does a longitudinal wave move?
the particles move parallel to the wave
What is the difference between mechanical and electromagnetic waves?
mechanical waves need a medium to travel through, and electromagnetic waves do not
How fast do electromagnetic waves travel in a vacuum?
300 million meters per second
What type of mediums can mechanical waves pass through?
solids, liquids, and gases
What type of medium do sound waves travel fastest through?
What type of medium do sound waves travel slowest through?
What is frequency?
the number of waves in a given amount of time
How do you calculate the speed of a mechanical wave?
divide the wavelength by wave period
How do you calculate the speed of a mechanical wave when you only have the wavelength and frequency?
multiply the wavelength and frequency
What is wavelength?
the distance from any point on a wave to an identical point on the next wave
What is an echo, when is it the strongest?
-it is a reflected sound wave
-strongest on smooth, hard surfaces
for example: flat painted ceilings and hardwood floors
What is reflection?
the bouncing back of a wave when it hits a barrier
How does temperature affect the speed of sound waves?
sound travels faster at higher temperatures rather than lower ones
What is resonance?
when a sound wave matches the natural frequency of an object and causes the object to vibrate
What materials absorb sound waves the best?
rough and soft materials
for example: carpet, acoustic tiles, and fabric curtains
How are ultrasonic waves used in a persons body?
they can pass through a person's body and reflect off of internal organs
What is sonar, how is it used?
it is electronic echolocation, and is used to locate objects underwater
What is echolocation, how do animals use it?
the use of reflected sound to find objects
How do different densities affect light waves?
light waves go slower through denser objects
What is light absorption?
the transfer of light energy to matter
What makes an object translucent?
it transmits light but scatters it in all directions
What makes an object opaque?
it does not let any light pass through it
What makes an object transparent?
when it transmits light
What is refraction?
the bending of a wave as it passes from one medium to another
What is scattering?
when light strikes matter and changes direction
Why are objects seen as certain colors?
all the colors but one are absorbed by the object, and the color we see is reflected
What is the difference between radio waves and sound waves?
radio waves do not require a medium to travel
What are waves?
disturbances that transfer energy from one place to another
What is wave period?
the time required for one wavelength to pass a given point
What is amplitude?
a measure of how far the particles in the medium move away from their normal rest position
What is frequency measured in?
What is interference?
when two or more waves overlap and combine to form one wave
What is constructive interference?
when waves overlap and combine to form a wave with a larger amplitude, or height
What frequencies do ultrasound use on the human body?
1 to 10 million Hz
How does a telephone handset change the incoming signals from a caller into sounds that you can hear?
it turns electrical signals into sound waves
What kind of waves are electrical signals changed into by a cordless phone?