Light and Sound Test Flashcards
(37 cards)
Scientific Notation - how to write numbers in scientific notation and how to do calculations with numbers in
scientific notation (see helpful videos posted on Canvas
knowwwwww itttt
Waves – know what the wavelength ( ), amplitude (A), and frequency ( ) are and common units for each;λ ν
be able to compare waves (how does their wavelength, frequency, etc. compare?)
wavelength- (lambda) how long a wave is (measured in meters)
Amplitude- how tall a wave is (A) (meters)
Frequency- (v) how frequent each wave would pass a line. (Hz)
What is light?
light is the visible portion of the electromagnetic spectrum
ROYGBIV - know relative wavelengths, frequencies, and energies (don’t need to memorize exact numbers
but need to know which has longest wavelength vs. shortest wavelength, etc.
ROYGBIV
goes from longer wavelength and lower frequency (R)
to
shorter wavelength higher frequency
Know the major types of electromagnetic radiation and their energies, frequencies, and wavelengths
In relationship to one another - you don’t have to memorize specific values but you should know which
has longer vs. shorter wavelengths, etc. – (Red Martians Invade Venus Using X-ray Guns
Radio
Microwave
Infrared
Visible
Ultraviolet
X-ray
Gamma Ray
Wavelength- long to short
Frequency- low to high
What is the numerical value of the speed of light (c)? (units for speed of light → meters/second)
3.0x10^8 m/sec
How does light travel?
in waves
Know the formulas c = wavelength x frequency and E = h x frequency (h, Planck’s constant,
will be provided) and be able to algebraically manipulate these equations to do various
calculations (see examples in textbook, Practice Problems for Light and Sound on Canvas,
and in Speed of Light Lab)
Understand the relationships between wavelength and frequency
and between energy and frequency
wavelength+frequency= inversely related
energy and frequency = directly related
Be able to identify the parts and functions of the eye (know cause of farsightedness and nearsightedness
and how these can be corrected with lenses - mentioned below again);
farsightedness- image doesn’t come into focus before it hits the retina= convex lens can bring the focus forward
nearsightedness- image comes into focus before it hits your retina = concave lens can push the focus back.
Know the “Law of Reflection”
and why you can see your reflection in some objects but not in others even though they all
reflect light
Law of reflection- angle of incidence= angle of reflection
most objects arent smooth enough to see yourself, the texture means that the rays don’t reflect straight back like a mirror they go all over the place.
Distinguish between plane, convex, and concave mirrors (seen in Reflection/Refraction Lab) and be able
to draw ray diagrams in order to determine whether an image would be upright or inverted, magnified or
diminished - know the uses of these types of mirrors; be familiar with the focal point/focus and center of
curvature (these would be labeled for you on an exam diagram) – **rules for ray diagrams posted on Canvas
What is refraction? When and why does it occur? How does the angle of incidence compare to the
angle of refraction? (seen in Reflection/Refraction Lab
refraction is the bending of light- occurs like a straw in water- (when one object passes through two different mediums.
angle of incidence does not equal the angle of refraction
What does the image through a pinhole camera look like? (seen in Reflection/Refraction Lab)
everything is upside down
Know that a prism splits white light into component colors - what is the order of the colors and which color
is refracted most/least?
prism refracts light-
ROY G BIV
red refracted least
Violet refracted more.
Colors - know the primary and secondary colors of light, primary and secondary colors of pigment, and how
these colors will combine (color diagram); also know the complementary colors of light and pigments (color
diagram
primaries of light: green red blue
secondaries of light: cyan yellow magenta
Primaries of pigment= cyan yellow magenta
secondaries of light = green red blue
complementaries are across from each other
Shadows (what property of light causes shadows?)
rectilinear propagation- light travels in a straight line until interrupted by an opaque object.
Opaque, transparent, translucent
Opaque= no light comes through
transparent= some light comes through
translucent- all light comes through
Reflection, Phosphorescence, Fluorescence
reflection- see colors of light that bounce off object, see the colors reflected
phosphorescence- absorbs visible light slowly and re emits it “glow in the dark”
fluorescence- absoravs visible and UV light then re emits it as visible- seen as brighter.
Types of light – natural sunlight, artificial fluorescent, incandescent
sunlight- gives continous spectrum- all colors present
flourescent- bright lines only- not continuos
incandescent- gives continuos spectrum, more like sunlight
What causes sound? How does sound travel? (compression, rarefaction)
sounds are caused by vibrations
travels in waves
compressions are the maximum point on a sound wave
Rarefractions are the minimum points on a pressure wave.
Know the characteristics of sound waves - wavelength, frequency, and amplitude and how these
are related to the pitch and loudness of a sound
Wavelength is just the length of the wave of sound (just like light)
Frequency is also called pitch
amplitude corresponds to a sounds loudness measured in decibles.
Speed of sound – how fast in air? How does that compare with speed in liquids and solids?
Can sound travel in a vacuum (absence of particles)? Why or why not?
SOLIDS- 6,000 m/sec
liquids- 1500 m/sec
air- 340 m/sec
No, theres no matter for compression and rarefracction- so therefore it is silent in space.
Distinguish between forced and sympathetic vibrations; give examples of each
Forced vibrations: when a vibrating object comes in contact with another option and causes it to vibrate as well.
(EX: phone on table)
Sympathetic Vibrations: occur when a vibrating object comes close to another object THAT HAS THE SAME NATURAL FREQUENCY, and the second object will start vibrating.
(EX: breaking a wine glass with your voice)