Properties of Waves

blockmindlessUrban and Civil

Nov 16, 2013 (3 years and 6 months ago)

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SCIE 111

Integrated Sciences I

Fac. Manuel
Laureano

Final presentation

Alvaro Rodriguez

members

Properties of Waves


Properties of Waves



Amplitude
:


Wavelength
:



Period
:



Frequency
:



Speed:


the height of the wave, measured in meters.

the distance between adjacent crests, measured in meters.

the time it takes for one complete wave to pass a given point,
measured in seconds.

the number of complete waves that pass a point in one
second, measured in inverse seconds, or Hertz (Hz).

the horizontal speed of a point on a wave as it propagates,
measured in meters / second.

Properties of Waves

Not all of these properties are independent; one
has the relations
:


Period = 1 / frequency

Speed = wavelength / period = wavelength x
frequency


Properties of Waves

Properties of Waves

Wave phenomena


Refraction


Dispersion


Interference of Waves


Diffraction


Double Slit Experiment Revisited


The Doppler Effect
.

Wave phenomena

Sound is the most common example of waves that
we encounter in our everyday life. A sound wave is
caused by the vibration of air molecules in
between the source and the listener; this is a clear
example of waves transferring energy from one
point to another without the transfer of matter.

Refraction of Waves



Refraction is very easily understood within the wave
model of light if one recalls that light slows down as
it enters a denser medium. If you imagine, a long
wave front approaching water from the air, as shown
below.


Dispersion of white light: in a
prism


Another aspect of light that is quite common is the breaking
up of white light into its constituent colors. For example, if a
beam of white light enters a glass prism, as shown in the
Figure below, what emerges from the other side is a spread
out beam of many colored light.



For constructive interference, the waves meet in phase, i.e. so
that the crests of each wave coincide. In destructive
interference, the waves meet out of phase, so that the crest
of one wave coincides with a trough of the other wave, and
they cancel each other out.



The final property of light we discuss is interference, a
phenomenon that occurs when two light beams meet.
Depending on the nature of the light beams and when they
meet, the two beams might enhance each other, to give a
brighter beam, or they might interfere in a way that makes the
total beam less bright. The former is called constructive
interference, whereas the latter is called destructive
interference.


Double slit interference

Interference effects

Plane and Circular


The Doppler Effect

Vis
ibl
e
sp
ect
ru
m

Maja

Hamoui

Visible spectrum


The visible spectrum is the portion of the
electromagnetic spectrum that is visible to the
human eye. Electromagnetic radiation in this
range of wavelengths is called visible light or
simply light. A typical human eye will respond
to wavelengths from about 390 to 750

nm.


In terms of frequency, this corresponds to a
band in the vicinity of 400

790 THz. A light
-
adapted eye generally has its maximum
sensitivity at around 555

nm (540 THz), in the
green region of the optical spectrum.



Visible wavelengths also pass through the "optical window", the region of the
electromagnetic spectrum that passes largely
unattenuated

through the Earth's
atmosphere. Clean air scatters blue light more than wavelengths toward the red,
which is why the mid
-
day sky appears blue. The human eye's response is defined
by subjective testing, but atmospheric windows are defined by physical
measurement.

Visible spectrum

The "visible window" is so called because it overlaps the human
visible response spectrum. The near infrared (NIR) windows lie just
out of the human response window, and the Medium Wavelength IR
(MWIR) and Long Wavelength or Far Infrared (LWIR or FIR) are far
beyond the human response region.

On the right is the infrared radiation,
the so
-
called heat radiation or IR. All
bodies emit radiation energy
characteristics of matter, and the
maximum exponent that occurs in the
infrared.

On the left is ultraviolet or UV
radiation that can be found mainly in
solar radiation is produced in electric
arcs
and

by some specialized devices
such as UV fluorescent tubes, also
called black light.


Many species can see light with frequencies outside the
"visible spectrum," which is defined in terms of human vision.
Bees and many other insects can see light in the ultraviolet,
which helps them find nectar in flowers. Plant species that
depend on insect pollination may owe reproductive success to
their appearance in ultraviolet light, rather than how colorful
they appear to humans. Birds, too, can see into the ultraviolet
(300

400 nm), and some have sex
-
dependent markings on
their plumage, which are only visible in the ultraviolet range


Color

Frequency

Wavelength

violet

668

789

THz

380

450

nm

blue

631

668

THz

450

475

nm

cyan

606

630

THz

476

495

nm

green

526

606

THz

495

570

nm

yellow

508

526

THz

570

590

nm

orange

484

508

THz

590

620

nm

red

400

484

THz

620

750

nm

The perception of color depends on the wavelength
when the light strikes a body, it better reflects some
wavelengths than others. This to be perceived by the
human eye determines the characteristic color of the
body. Of course, the perception of each color varies from
person to person.

In 1666, Isaac Newton made ​​his first experiments on the colors produced by
passing a narrow beam of light through a prism
.

Newton
defined the spectrum as the orderly

arrangement
of colors from violet to red.

He
believed that some imperfection in the

glass
was the cause of the spectrum, and to verify his guess, he produce a
spectrum through a prism with impinges, but oriented inversely (opposite).

If the spectrum was caused by irregularities in the second prism, it should
have increased the widening of the colors. Instead, it formed a point of white
light. After further experiments, he became convinced that white light
consists of colors. Today we know that each color in the spectrum is
associated with a specific wavelength.

At
the beginning, we said that the
rainbow is a consequence of the
decomposition of light.

Now, in simple explanation, we say that a
rainbow forms when sunlight passing
through raindrops. Sunlight is composed
of all colors, which produced mixed
lighting. When sunlight penetrates the
water droplets, it’s reflected in the
interior surfaces. While passing through
drops, the light is separated into its
component colors, producing an effect
very similar to a prism. Obviously, this
dispersion occurs in all the droplets that
are exposed to sunlight

In more scientific way, the rainbow is an
optical phenomenon produced by the
scattering of sunlight when it is refracted
and reflected in the drops of rain. This
sunlight is separated into components,
resulting in a bright arc formed by the
various colors of the rainbow. The color
red is refracted the least and is on the
outside of the arc, turning towards the
interior, orange, yellow, green, blue,
indigo and violet.

How Energy Is
Transmitted

How Energy Is Transmitted


Energy is an electrical charge that is
composed of sub
-
atomic particles .


The matter is influenced by electromagnetic
fields ; the interactions between the electric
charge and field is the source of the four
fundamental interactions.


The particle that carries the information of
these electromagnetic interactions is the
photon, which takes time.


How Energy Is Transmitted


The amount of time a photon takes is determined
by T=C/D; where C is the speed of light in the
medium which transmits, while D is the distance
between the charges.


Energy is manifested in many phenomena,
including mechanical, thermal, light, and
chemical.


Energy can be naturally observed in the rays that
are produced by electrical discharges of energy
transfers between the ionosphere and the
ground’s surface.


Different Forms of Energy


Thermal Energy: The sum of the kinetic and
potential energy of the particles in an object
due to their random motion. Example: the
liquid in a thermometer expands when its
temperature increases.


Different Forms of Energy

Chemical
Energy: Is the energy stored in
chemical bonds. Example:

During
photosynthesis, green plants use
radiant
energy from the sun to produce chemical
compounds which are eaten by humans.


Different Forms of Energy


Radiant Energy: Is energy that travels in the
form if waves. The sunlight that reaches earth
is radiant energy that travels through space as
electromagnetic waves. Example: radio waves,
microwaves, light and x
-
ray waves.


Different Forms of Energy


Electrical
Energy: Is carried by electrical
currents. Example: Cd players



Different Forms of Energy


Nuclear
Energy: Is when changes occur in the
nuclei of an atom.


Different Forms of Energy


Kinetic Energy: Depends on mass and speed
Example: a bowling or tennis ball in
movement.



Different Forms of Energy


Potential
Energy: Is stored energy in an object
that is not in motion due to its position .
Example: When you lift a back pack you cause
its position to change.



Energy

Links


'The God Particle': The Higgs Boson


http://youtu.be/1_HrQVhgbeo


Electromagnetic Spectrum: Radio Waves


http://youtu.be/al7sFP4C2TY



Sound, Vibration, Wave Characteristics


http://youtu.be/dbeK1fg1Rew



References


http://www.school
-
for
-
champions.com/science/waves.htm


http://theory.uwinnipeg.ca/mod_tech/node119.html


http://theory.uwinnipeg.ca/mod_tech/node124.html


http://theory.uwinnipeg.ca/mod_tech/node125.html