SCIENCE 101 1

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SCIENCE 101 1 An Introduction to Science
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• Science 101Quiz
• 9/27/02
• Absolute 0 ________K __________C
• 0 C ________K
• Freezing is _________C __________F
• Boiling is _________C __________F
• 500 K _________C
• Calculate the efficiency of a coal-fired
  generating plant if the high-energy steam is 800K
  and room temperature, the low temperature
  reservoir, is 300K.
• 5. How much electrical current will flow through
  a 250 watt stereo system to play a compact disk
  in a 110 volt outlet?

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Chapter 6 Waves and Electromagnetic Radiation
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A can be described as a
disturbance that travels through a medium
transporting energy from one location to another
location.
wave
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The section of the wave that rises above the
undisturbed position is called the crest. That
section which lies below the undisturbed position
is called the trough.
http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htm
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Amplitude is the maximum positive displacement
from the undisturbed position of the medium to
the top of a crest.
http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htm
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http//id.mind.net/zona/mstm/physics/waves/partsO
fAWave/waveParts.htm
Wavelength is the distance between crests.
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Frequency is the number of wave crests that go by
a given point every second.
If five waves are made per second the frequency
is five cycles per second, 5 cps 5 Hz One
cycle per second is one Hertz 1 cps 1 Hz
Velocity is the speed and direction of the wave
crest. Wave velocity (m/s) wavelength (m) x
frequency (Hz) V ? ?
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http//hyperphysics.phy-astr.gsu.edu/hbase/hframe.
html
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Transverse wave - A transverse wave is a wave in
which the motion of the medium is perpendicular
to the motion of the wave.
The motions of the medium Is up and down. The
motion of the wave Is to the right or to the
left.
http//www.infoline.ru/g23/5495/Physics/English/wa
ves.htm
Water waves are mostly transverse. The water
moves up and down while the wave travels over the
surface of the water.
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Longitudinal wave - A longitudinal wave is a wave
in which the motion of the medium is parallel to
the motion of the wave.
The motions of the mediumIs to the right or to
the left.The motion of the waveIs to the
right or to the left.
http//www.infoline.ru/g23/5495/Physics/English/wa
ves.htm
Sound waves are longitudinal. The air vibrates
back and forth along the same direction as the
wave is traveling.
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Sound Waves
Since a sound wave is a disturbance which is
transported through a medium via the mechanism of
particle interaction, a sound wave is
characterized as a mechanical wave.
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Sound Waves
Sound waves are longitudinal waves.
http//www.glenbrook.k12.il.us/gbssci/phys/Class/s
ound/u11l1b.html
The loudness of sound is the amplitude. High
frequency sound waves (short wavelengths) we hear
as high pitches. Low frequency sound waves
(long wavelengths) we hear as low sounds.
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Sound Waves
Sound travels about 340 meters per second. Organ
pipes have a wavelength twice as long as the
pipe. Remember Wave velocity (m/s)
wavelength (m) x frequency (Hz)
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Interference
When waves from two different sources come
together at a single point, each wave interferes
with the other.
http//www.glenbrook.k12.il.us/gbssci/phys/Class/s
ound/u11l3a.html
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http//hyperphysics.phy-astr.gsu.edu/hbase/hframe.
html
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Electromagnetic Waves
Electromagnetic waves can be described by their
wavelengths, energy, and frequency. All three
describe a different property of light, yet they
are related to each other mathematically. It is
correct to talk about the energy of an X-ray or
the wavelength of a microwave or the frequency of
a radio wave. X-rays and gamma-rays are usually
described in terms of energy, optical and
infrared light in terms of wavelength, and radio
in terms of frequency.
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Electromagnetic Waves or Electromagnetic Radiation
Maxwell described these waves which transfer
energy through electric and magnetic fields. The
velocity of these waves he found to be 300,000
kilometers per second - the speed of light (c).
Maxwell discovered that light and other kinds
of radiation are a type of wave that is generated
whenever electrical charges are accelerated.
Once they start moving, they no longer depend on
the source.