Flashcards in sound, light, and electricity test Deck (44):
what is sound?
types of waves
what is a wavelength?
distance from identical parts of a wave
what is an amplitude?
height of a wave from the rest positionq
what is frequency?
number of complete waves that pass a fixed point in a given time (change in pitch)
what is reflection?
when a wave strikes a surface and bounces off of it
what is refraction>
the bending of wabes as they enter a new medium-bending occurs due to the chanfe of speed in the wavee
what is diffraction?
change in behavior of a wave as it encounters obstacles
what is the doppler effect?
the apparent change in frequency of a wave as the source moves in relation to the observer *move by ear*
what is resonance?
when an oject is struckby a wave that matches it's natural frquncy, the object will vibrate
what is the perception of sound?
the distance from the source, or amount of energy required
what is intensity?
the amount of energy a sound wave carries per second through a unit area
what is pitch?
how high or low a sound seems to an observer
what are photons?
"packets" of light energy
what is a particle model?
when light shines on surfaces, electrons on that surface became "excited"
what is a wave model?
waves of light travel as two interlocking transverse waves at 90 degree angles to each other (polarized filters)
what is the photoelectric efffect?
-discovered by Einstein
-when light hits a substance, the electrons can become so "excited" that they are essentially kocked off of the substance
what is electricity?
a flow of electrons from place place
what is a gradient?
a difference in concentration of something
what is a current?
continuous flow of electrons, measured in amps
what is voltage?
the difference in electrical potential in a circuit, measured in volts (also called potential difference)
what is resistance?
opposition to the flow of a current, measured in ohms
what is ohms law?
v = i x r
types of circuits?
series, parallel, complex
what is a series circuit?
only 1 continuous path for electricity to travel
what is a parallel circuit?
multiple paths for electricity
factors affecting resistance?
-diameter of wire
-length of wire
-temp. of wire
-type of wire
what is the series circuit equation?
what is the parallel circuit equation?
Rt+ 1/ ( 1/R + 1/R + 1/R)
in a series circuit, what is constant?
in a parallel circuit, what is constant?
who was luigi galvani?
1780, researched frogs
-galvani was dissecting a frog on a table, and there was a spark
who was alessandra volta?
took galvani's research to make the first battery
what was the first battery made from?
volta layered zinc, paper soaked in salt water, and silver
what is an electrade?
piece of metal sitting in an electrolyte
what is an electrolyte?
a substance, liquid or paste, that conducts electric current
what is a terminal?
the part of the electrolyte that sticks out of the electrolyte
what is a battery?
a combination of 2 or more electrochemical cells
what are wet cells?
when the electrolyte is a liquid
what are dry cells?
when the electrolyte is a paste
what does electricity follow?
the path of least resistance
what is static electricity?
when electric charges build up on the surface of an object
called "static" because the charges don't flow (no current)
what is friction?
when 2 uncharged objects rub together creating a charge on 1 of the objects
what is conduction?
when a charged (static discharge) object transfers charge to another by direct contact