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162 Cards in this Set
- Front
- Back
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The nucleus is surrounded by ____ charged electrons.
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negatively
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_____ and _____ are in the nuclei of atoms except for Hydrogen.
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Protons and Neutrons
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Atoms in metal conduct electricity the best.
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Copper
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Passing charge without touching something____.
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induction
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Passing charge by touching something_____.
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conduction
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_____ energy associated with charged particles as they move from place to place.
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Electricity
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Electricity's moving particles are usually______, but any charged particles will do.
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electrons
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Like charges_____ and opposites ______.
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repel
attract |
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The amount of positive charge of the proton is _____ to the amount of negative charge in the electrons.
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equal
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More electrons than protons means ____ charged atom.
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negatively
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Charged particles are near one another a force of_____ is the result.
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attraction or repulsion
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Region surrounding a charged particle in which forces of attraction or repulsion are noticed.
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Electric Field
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Friction
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object's whose electrons are loosely bound rubs against another object electrons are transferred to the 2nd object.
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Measure of energy available to move electrons.
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Voltage
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Voltage is the electric____ between two points.
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potential difference
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Build up of electrical charge on the surface of objects. Requires separation of positive and negative charges.
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Static Electricity
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Describes the electric force between two charged particles
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Coulomb's law F=k q1q2/d2
q1 and q2= 2 quantities of charge unit of charge= Coulomb |
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____ or _____ is measured in volts and abbreviated V.
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Voltage or electric potential
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Batteries are ____ v.
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1.5
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___batteries are used in smoke detectors, pocket radios, and fuzz boxes. ______ batteries are for cars.
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9v and 12v
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____lines have many thousands of volts between them.
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high voltage
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Unit of electrical potential=
Electric potential= |
volt
voltage 1 volt=1 Joule/ coulomb |
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The difference in electrical potential is called the
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potential difference
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Ends of electrical conductor are at different electric potentials, charges will flow from
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higher potential to lower end
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The rate of electrical flow is measured in
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Amperes (A)
1A=1C/s |
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Water flows through a pipe if there is a difference in pressure
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across or between its ends
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Electrical Charges flow through a circuit because of applied voltage
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across a circuit
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Currents approaching ____ are lethal if they pass through sensitive portions of the body.
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.1A
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Luckily the body has_____so it takes a substantial voltage to drive that much current.
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fairly high resistance
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Dry skin is a ____ conductor.
Wet skin is a ____ conductor. |
poor, 50,000-100,000
good, 100-1000 |
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The flow of charged particles
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electric current
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In a conductor such as wire, the flowing electric charge is usually carried by________.
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moving electrons
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The flow of electric charge can also be carried by____ in an electrolyte.
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ions
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____ flows in one direction only, it is produced and stored when electrical potential is tapped.
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Direct Current(Edison)
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Batteries and solar cells have____.
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electrical potential
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Any path in which electrons can flow______.
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Circuit
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For a continuous flow of electrons you must have a ________.
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complete circuit with no gaps
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Electrical devices connected to the same circuit_____.
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parallel
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When you increase the # of parallel branches
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the overall resistance is decreased
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Rate at which electric energy is converted into another form____.
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Electric Power
power=current x voltage power= I x V |
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Current has a ____ pathway.
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single
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Sum of the individual resistances along circuit path.
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Total Resistance
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In a circuit electric current powers____, which have a certain amount of resistance to the current flow that keeps the current from reaching very large values.
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appliances
houses, voltage is parallel |
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Magnets have ______ and _____. Like poles repel eachother and opposite poles attract.
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North Poles and South Poles
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Iron fillings sprinkled around a magnet trace out a _______.
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magnetic field
field is stronger where lines are closer together |
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The Earth has a ____ magnetic field inside it.
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south
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A moving charged particle causes a _____.
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magnetic field
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_____ is a magnet whose field is produced by an electric current. Iron Core like the one we used in lab.
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electromagnet
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The pole near the geographic north pole is sometimes called the _____.
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geomagnetic north pole
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A device that uses current, carrying coil forced to rotate in a magnetic field to convert electrical energy to mechanical energy.
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electric motor
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Faraday and Henry discovered that electric current can be produced in a wire by
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moving a magnet in and out of a coiled wire.
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Voltage is ____ by the relative motion between a wire and a magnetic field.
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induced
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When a magnet is moved in and out of a coiled wire____.
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direction of induced voltage and current alternates
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Greater voltage is induced in secondary if
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secondary has more turns than primary
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Greater voltage is induced in primary
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Step down transformer
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Induced voltage in coil is proportional to number of loops times the rate at which the magnetic field changes within the loops.
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Faraday's Law.
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If the magnetic field of a current carrying wire can be "intercepted" by the 2nd coil
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voltage is induced in the 2nd coil
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device for transferring electric power from one coil to another
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transformer
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Input coil _____.
Output coil _____. |
primary
secondary |
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So that primary affects the secondary..
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coils need to be wound around a common iron core, and not touch each other.
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High Voltage Lines
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transport large amounts of electrical power over long distances.
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Its easier to reduce an AC high voltage to low voltage using a ______.
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step down transformer
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Ice crystals in the clouds that steal electrons
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lightning
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Wave pulse is started with vibration and is transmitted through
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the medium which it travels.
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A wave travels
through a medium, but the individual particles . |
just move
up and down |
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Light waves are
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transverse
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SOund Waves are
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Longitudinal
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Wave encountering more dense medium will be
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partly reflected partly transmitted
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Amplitude
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max height of peak
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wavelength
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distance between sucessive peaks
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frequency
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# of peaks that pass a given point per unit of time
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Period T
Period |
time required for one cycle
1/frequency |
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By multiplying the period of a wave with the speed of light
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we can determine wavelength
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Transverse wave
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oscillations are perpendicular to the direction of wave motion
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Longitudinal Wave
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oscillations are parallel to the direction of motion
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When two waves pass through the same region
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they interfere
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Interference may either be ____ or ______.
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constuctive or destructive
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Constructive waves ______ and Destructive waves_____.
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come together perfectly, can each other out
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Two waves meet an obstacle bending around it leaving a shadow region
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diffraction
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Diffraction depends on
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the size of the obstacle compared to the wavelength, the wave is barely affected if the obstacle is much smaller
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Sound can travel through any kind of matter, but cannot travel through ____.
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vaccuum space
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SPeed of sound is fastest in ____and slowest in ____.
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solids, gases
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Wave speed depends on ____ especially for gases.
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temp
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There is no medium for sound to travel through
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outer space
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Loudness is related to the ___ of the sound wave.
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amplitude
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The shorter the wavelength the ____ the frequency becomes.
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higher
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Audible range of frequency is ____ to ______. Ultrasound range is above _____.
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20 Hz, 20,000 Hz, 20,000 HZ
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Sound waves are collected by the outer ear and funneled toward the eardrum. Sound waves vibrate the eardrum.
The three bones of the middle ear transmit the vibrations toward the inner ear. Fluid in the inner ear stimulates nerve endings. Electrical impulses are sent from the _____ along the auditory nerve to the brain. |
nerve endings
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When disturbed, an object _____ at its own set of frequencies (natural frequency).
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vibrates
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When vibrations are forced on an object that match its natural frequency, __________ occurs (resonance).
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a dramatic increase in amplitud
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A _______ is a wave that remains in a constant position.
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standing wave
This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling in opposite directions. |
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Standing waves are observed in ______ of air. Any waves traveling on the medium will reflect back when they reach the end.
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strings and columns
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This ____ allows sound waves to resonate inside. Raising or lowering the water changes the length of the tube.
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resonance tube
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When the string is stretched and child speaks into one cup, the sound can be heard at the other cup.
Why? |
When two sound waves of different frequency approach your ear, the alternating constructive and destructive interference causes the sound to be alternatively soft and loud - producing beats.
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The______ is the apparent change in wavelength of a wave for an observer becaue the source of the waves is moving.
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Doppler Effect
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Source moving toward an observer, waves are shorter. ____. Source moving away from an observer, waves are longer. redshift.
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blueshift
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If a source is moving faster than the wave speed in a medium, waves cannot keep up and a _____is formed.
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shock wave
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Aircraft exceeding the speed of sound in air will produce two ______, one from the front and one from the tail.
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sonic booms
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______ is used to locate objects underwater by measuring the time it takes a sound pulse to reflect back to the receiver.
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Sonar
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Sonar usually uses ______, as the shorter wavelengths are less likely to be diffracted by obstacles.
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ultrasound wave
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The creation of an image from sound is done in three steps -
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producing a sound wave, receiving echoes, and interpreting those
echoes. |
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In 1860, _________unified the theories of electricity and magnetism and showed that electric and magnetic fields travel through space together in the form of electromagnetic waves.
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James Clerk Maxwell
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-- A wave emitted by vibrating electrical charges and composed of vibrating electric and magnetic fields
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Electromagnetic Wave
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Classified by frequency or wavelength.
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Includes radio waves, microwaves, infrared, visible light, ultraviolet, gamma rays.
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Electromagnetic radiation travels through empty space at the
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speed of light.
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The frequency, f of a wave is related to the number of completed periods in one second.
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The speed of the wave is equal to the wavelength times the frequency.c=*f orv=*f
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Radio waves have the ____ wavelengths in the electromagnetic spectrum.
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longest
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developed means to reliably produce radio frequency currents, publicly demonstrated the principles of radio, and transmitted long distance signals.
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Nikola Tesla
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Particles in our atmosphere that are about the same size as the wavelengths of visible light cause the
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light from the Sun to scatter and split into individual colors.
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________, the main components of our atmosphere, scatter violet and blue light due to their small size (wavelength). This is why the sky appears to be blue in the daytime
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Oxygen and Nitrogen
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At sunrise and sunset the distance that the light has to travel from the Sun to our eyes is at its _____. It’s going through a much thicker section of the atmosphere.
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greatest
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Most of the shorter-wavelength blue and violet light has already been scattered by the atmosphere, so the light that is seen by our eyes is mainly the long-wavelength______.
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red
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Light from the Sun looks as though it is white, but actually it consists of 7 colors.
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ROYGBIV = Red, Orange, Yellow, Green, Blue, Indigo, Violet
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The splitting of white light into its color components is called .
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Dispersion
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Low Frequency=
high frequency= all colors blended= |
red
blue white |
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Light rays approaching the surface of a mirror at an angle will bounce off on the opposite at the same angle at which they approach.
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This is the Law of Reflection.
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Light rays traveling from air into a transparent medium such as glass bend at the surface. The bending of light rays between two different materials is called
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refraction.
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The angle at which each color emerges from a raindrop is different (or else you wouldn't see different colors):
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red light emerges at 42° and blue light emerges at 40.6° relative to the incoming ray of sunlight.
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Basic parts of a camera:
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Lens Light-tight box Shutter
Film or electronic sensor |
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In a sense, the _____ expands the "useful aperture" of your digital camera or telescope.
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CCD
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The closest distance at which eye can focus clearly. Normal is about 25 cm.
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Near point:
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The farthest distance at which object can be seen clearly. Normal is at infinity.
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Far point:
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far point is too close.:
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Nearsightedness
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: near point is too far away.
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Farsightedness
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A nearsighted eye, which cannot focus clearly on distant objects, can be corrected by use of a diverging lens
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concave
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A farsighted eye, which cannot focus clearly on nearby objects, can be corrected by use of a converging lens.
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convex
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use mirrors to gather and collect light.
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Reflecting Telescopes
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Telescopes use lenses to gather and collect light.
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Refracting
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A large telescope increases the image sharpness and the extent to which fine details can be distinguished.
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Resolving Power:
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Magnifying power is the ability of the telescope to make an image appear large in the field of view.
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Magnification:
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The ability of telescope to see small details so that objects that are close together in the sky are seen as separate.
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Angular Resolution
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The__ and___ powers of a telescope are much more important, as the magnification can be changed simply by switching eyepieces.
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light-gathering and resolving
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_____ lens to gather light and an eyepiece through which the image is viewed.
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objective
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This failure of a lens to focus all colors is called
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chromatic aberration.
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The large mirror used to gather and focus the light in a reflecting telescope is called the
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primary mirror.
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The surface of the mirror used is ______ (parabolic). Parallel light rays from distant objects converge to a focal point.
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bent into a curve
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The distance between the mirror and its focal point is called the
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focal length.
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A _____ uses a flat secondary mirror to redirect the focused image to the side of the telescope for viewing. The image is viewed through a small focal length lens called an eyepiece.
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Newtonian telescope
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In a _____, light strikes the primary mirror and reflects the image back to the smaller secondary mirror, which reflects the magnified image through the center hole and on to the eyepiece.
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Cassegrain telescope ( what we use)
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A _______ is compact and gives excellent results, but the secondary mirror obstruction reduces image contrast.
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Schmidt-Cassegrain
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The transparency of a material depends on the ________. Earth’s atmosphere is relatively transparent to visible light and radio waves, which are referred to as “windows” through which we can view space from a ground-based telescope.
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wavelength of light
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A radio telescope must be ____ than an optical telescope to make images of comparable clarity.
Radio waves are not affected by daylight or cloudy weather, so observations can be made 24/7, 365.25 days a year. |
larger
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The _____ is the largest single aperture telescope ever constructed.
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Acrecibo
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In order to make more clear (or higher resolution) radio images, astronomers often combine several smaller telescopes or dishes into an
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array.
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The dishes can act as one large telescope whose size equals the total area occupied by the array
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(interferometry).
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The_______ is the world's largest fully steerable radio telescope and the world's largest land- based movable structure.
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Green Bank Telescope
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is a technology to improve the performance of astronomical telescopes by reducing the effects of atmospheric distortion (twinkling) or changes in mirror shape.
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Adaptive optics
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Image shows the Cat's Eye Nebula (NGC 6543) seen in __ light. This animation cycles between the visible-light view which is blurred by Earth's atmosphere and a corrected image using Palomar's AO System
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visible
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_____ of the Sun reveal details that cannot be observed in the visible spectrum.
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Non-optical images
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Sometimes light acts like a particle and sometimes it acts like a wave.
It all depends on what sort of experiment you're conducting. |
This is known as wave/particle duality.
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When light of a single color is passed through two slits, the light from the two sources creates an interference pattern of bright and dark regions.
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This shows that light is a wave.
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Max Planck was working on the relationship between the radiation emitted by an object and the object’s temperature.
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He derived an equation that agreed with his data, but the equation only made sense if Planck assumed that the energy of a vibrating molecule was quantized-- that is, it could only take on certain values.
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Energy would have to be _____ to frequency, and it seemed to be in multiples of the frequency times a constant.
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proportional
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Light consists of little particles, called photons (or quanta), each with an energy that is found by:
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Photon Energy= Planck's Constant(6.626x10^34)/ wavelength
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Shows that light exhibits particle behavior
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Photoelectric Effect
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If light hits an electron in one of the atoms in the metal, it might transfer enough energy to knock the electron away from its atom.
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Light carries energy.
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It was found that for each metal, there is a threshold frequency. Light frequencies ____ the threshold eject no electrons, no matter how intense the light.
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below
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Light frequencies _____ the threshold eject electrons, no matter how low the intensity.
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above
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When the light source is turned on, the electrons begin to be _____.
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ejected immediately.
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expoplanet
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planet outside solar system
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Orbiting a star
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found by Kepler
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If Earth had no atmosphere it would be
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black
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