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RECOGNIZE WHAT FACTORS AFFECT THE SPEED OF SOUND1. MEDIUM -rubber slows
vibrations, used as soundproofing
2. Temperature -higher the
temperature, faster the sound
3. STATES OFMATTER -In gas depends on velocity and mass
-travels fastest in solids, then liquids because of orientation of molecules
RELATE LOUDNESS AND PITCH TO PROPERTIES OF SOUND WAVES
1. LOUDNESS
-greater the amplitude, louder the sound
-distance from source
- measured in decibels (120 dB deafness)
1. PITCH - How high or low a note
sounds - high pitch made by
rapid vibrations - low pitch made by slow
vibrations -humans hear between
20-20000 vibrations(Hz)
Explain how harmonics and resonance affect the sound from
musical instruments1. How instruments
work: - grouped strings, air,
column, membranes - work by standing
waves: - change pitch by
changing length of strings, or opening of holes
- Fundamental frequency: frequency of the string’s vibrations
1. HARMONICS - when the instrument has
fundamental frequency and whole number multiples of that frequency (complex wave)
-unique sound of each instrument comes from the relative intensity of different harmonics in each note
2. RESONANCE - instrument vibrates in
response to strings vibrating - natural frequencies: response
of instrument to vibrate at certain specific frequencies in tune with the strings
- natural frequency: instrument’s mass, shape and size, medium
- amplified- instruments need this if do not resonate well
Describe the function of the ear
Explain how sonar and ultrasound imaging work
1. Sonar (sound navigation
and ranging) a. Distance to
ocean floor D=1/2vt
b. organisms that use sonar: bats, dolphins, whales
ULTRASOUND IMAGING
1. SONOGRAMS frequency of 1 million-15 million Hz A. MEDICAL USES OF: a. diagnose problems b. guide surgical procedure c. view unborn fetuses B. NONMEDICAL USES OF: a. locate hairline fractures in metal support
beams and machinery b. clean jewelry, dentures, and small machinery2. ADVANTAGE of ultra vs x-ray a. doesn’t harm living cells
Section 12.1 review questions
1. What is the human range of hearing?
2. Musical instruments produce ___waves?
3. What does harmonics do for instruments?
4. What does resonance do for instruments?
Medium Speed of sound
Gases
Liquids
solids
Review for Ear
1. Try to sketch and label from memory the parts of the ear.
2. Name the regions of the ear?
3. Where does resonance occur in the ear?
1. What is sonar?2. Name 3 organisms
that use sonar.3. Give the formula used
to determine depth using sonar.
4. What is a sonogram?5. Name 5 medical uses
of Sonar.6. What is the advantage
of sonar over x-rays?7. Name 3 nonmedical
uses of Sonar
Recognize that light has both wave and particle
characteristicsWave characteristics a. 1801 Thomas
Young interference
pattern in light so modeled wave
b. model supported by interference, reflection, and refraction
Particle characteristics a. 1905 Albert Einstein
explain photoelectric effect
b. photons are bundles of energy which can eject elecrtons from a metal plate
c. model is supported by dim blue light knocking electrons off a metal plate while bright red light cannot.
d. Explains how light can travel without a medium
Relate the energy of light to the frequency of
electromagnetic waves
Electromagnetic spectrum
Uses of electromagnetic waves
Review for section 12.21. Light is described as a transverse wave that
doesn’t require a ______ to travel2. Who introduced photons?3. Photons do not have mass, they are more like
little bundles of ______.4. Most scientists accept both models of light.
Some believe that light has a “_______ ______”
5. Speed depends on _____.6. What happens to speed of light as medium
density increases?7. Brightness depends on ______ or the number
of photons or waves.
OCCURANCES PORTION OF ELECTROMAGNETIC
SPECTRUM
RADAR
SMALLEST PORTION OF THE ES
TELECOMMUNICATION
HIGHEST ENERGY WAVES
TV SIGNALS
CAUSES SUNBURN
USED BY RESTAURANTS TO KEEP FOOD WARM
HEAT
AM/FM
USE SUNSCREEN FOR PROTECTION
IMMEDIATELY ABOVE VISIBLE LIGHT IN THE ES
SHORTEST WAVELENGTH
COOKING
LONGEST WAVELENGTH
CAN PRODUCE IMAGES OF BODY ORGANS
Describe how light reflects off smooth and rough surfaces
1. Rough surfaces:a. Diffuse reflection:
Light rays are reflected in many directions
1. Smooth Surfaces: A. light rays are reflected in one
direction a. angle of incidence: striking
surface rays b. angle of reflection:
reflecting light rays c. normal: line perpendicular to
the surface at the point where the light hits the mirror.
Explain the law of reflection
1. LAW of REFLECTION:
THE ANGLE OF INCIDENCE EQUALS THE ANGLE OF REFLECTION
- Angle of incidence and angle of reflection are measured from the normal, not from the surface of the mirror
Show how mirrors form real and virtual images
1. Flat mirrors form virtual images by reflection
a. virtual image: an image that forms at a point from which light rays appear to come but do not actually come
b. appears to exist in a certain place but there are no light rays there
2. Curved mirrors distort images
convex mirrors: bulge out
concave mirrors: indented in
3. Concave mirrors create real images
a. real image: an image of an object formed by many light rays coming together in a specific location
b. light rays really exist at the a point where the image appears
Objects have color because they reflect certain wavelengths of light( all other light is absorbed)
a. brain receives signals from certain comb. of photoreceptors cells in the retina
b. receptors are three kinds of cone cells, one each for red, green, and blue.
c. Color is just the way our brain interpret certain signals
Explain why objects appear to be different colors
Describe how colors may be added or subtracted
• Additive primary colors: red, green and blue
• Secondary colors: yellow, cyan, and magenta
• Subtractive primary colors: reverse secondary colors to reproduce primary
• Black: the absence of color
• http://www.sciencemuseum.org.uk/on-line/outofsight/illusions.asp