Grade 8 Science Independent Learning Packets - Tunica County School District
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Tunica County School District
Science
Independent Learning
Packets
Grade 8
April 6-10, 2020
Student Name: __________________________
WEEK 3 – 8TH GRADE REVIEW
CONTENT STRAND: PHYSICAL SCIENCE
DAY 1
Introduction To Waves
April 6-10, 2020 1
Complete the following questions about waves.
1. Name the labeled parts in the diagram below.
A. ______________________________
B. ______________________________
C. ______________________________
D. ______________________________
E. ______________________________
F. ______________________________
2. What is frequency? ____________________________________________________
3. What is amplitude? ____________________________________________________
4.
The diagram above is a visual representation of the voices of a three-member singing
group. They each sing different parts in the trio. One member sings high soprano,
another member sings alto, and the third member sings bass (low, deep).
Which wave represents the bass member? _________________
Which wave represents the alto singer? ____________________
Which wave represents the soprano singer? ____________________
April 6-10, 2020 2DAY 2
Converting Wave Energy into Electricity
https://www.youtube.com/watch?v=70K0uQmb-bs
https://www.conserve-energy-future.com/waveenergy.php
http://www.alternative-energy-tutorials.com/wave-energy/wave-energy.html
How is Wave Energy Converted into Electricity?
In order to harness wave energy and make it create and energy output for us, we have to go
where the waves are. Successful and profitable use of wave energy on a large scale only
occurs in a few regions around the world. The places include the states of Washington,
Oregon and California and other areas along North America’s west coast. This also includes
the coasts of Scotland Africa and Australia.
Wave energy is, essentially, a condensed form of solar power produced by the wind action
blowing across ocean water surface, which can then be utilized as an energy source. When
the intense sun rays hit the atmosphere, they get it warmed up. The intensity of sun rays
hitting the earth’s atmosphere varies considerably in different parts of the world. This
disparity of atmospheric temperature around the world causes the atmospheric air to
travel from hotter to cooler regions, giving rise to winds.
As the wind glides over the ocean surface, a fraction of the kinetic energy from the wind is
shifted to the water beneath, resulting in waves. As a matter of fact, the ocean could be seen
as a gigantic energy storehouse collector conveyed by the sun rays to the oceans, with the
waves transporting the conveyed kinetic energy across the ocean surface. With that in
mind, we can safely conclude that waves are a form of energy and it’s the same energy, not
water that glides over the surface of the ocean.
These waves are able to travel throughout the expansive oceans without losing a lot of
energy. However, when they reach the shoreline, where the depth of water is considerable
shallow, their speed reduces, while their size significantly increases. Ultimately, the waves
strike the shoreline, discharging huge quantities of kinetic energy.
Identify three advantages of using wave energy to produce electricity.
1. ____________________________________________________________________
2. ____________________________________________________________________
3. ____________________________________________________________________
April 6-10, 2020 3DAY 3
Sound Waves
Read and annotate the following article.
Behavior of Sound Waves
Reflection, Refraction, and Diffraction
Like any wave, a sound wave doesn't just stop when it reaches the end of the space through
which it is traveling or when it encounters an obstacle in its path. Rather, a sound wave will
undergo certain behaviors when it encounters the end of the space or an obstacle. Possible
behaviors include reflection off the obstacle, diffraction around the obstacle, and transmission,
accompanied by refraction, into the obstacle or into a new space.
Reflection and Transmission of Sound
When a sound wave reaches the boundary between one space and another, a portion of the
wave undergoes reflection and a portion of the wave undergoes transmission across the
boundary. The amount of reflection is dependent upon the dissimilarity of the two spaces. For
this reason, acoustically minded builders of auditoriums and concert halls avoid the use of
hard, smooth materials in the construction of their inside halls.
A hard material such as concrete is as dissimilar as can be to the air through which the sound
moves; subsequently, most of the sound wave is reflected by the walls and little is absorbed.
Walls and ceilings of concert halls are made of softer materials such as fiberglass and acoustic
tiles. These materials are more like air than concrete and thus have a greater ability to absorb
sound. This gives the room more pleasing acoustic properties.
Reflection of sound waves off surfaces can lead to one of two phenomena - an echo or
a reverberation. A reverberation often occurs in a small room. Perhaps you have observed
reverberations when talking in an empty room, when honking the horn while driving
through a highway tunnel or underpass, or when singing in the shower.
Reflection of sound waves also leads to echoes. Echoes are different than reverberations.
Echoes occur when a reflected sound wave reaches the ear more than 0.1 seconds after the
original sound wave was heard. If the elapsed time between the arrivals of the two sound
waves is more than 0.1 seconds, then the sensation of the first sound will have died out. In
this case, the arrival of the second sound wave will be perceived as a second sound rather
than the prolonging of the first sound. There will be an echo instead of a reverberation.
Perhaps you have seen a museum exhibit that utilizes a parabolic-shaped disk to collect a
large amount of sound and focus it at a focal point. If you place your ear at the focal point,
you can hear even the faintest whisper of a friend standing across the room. Parabolic-shaped
satellite disks use this same principle of reflection to gather large amounts of electromagnetic
waves and focus it at a point (where the receptor is located). Scientists have recently
discovered some evidence that seems to reveal that a bull moose utilizes his antlers as a
satellite disk to gather and focus sound. Finally, scientists have long believed that owls are
equipped with spherical facial disks that can be maneuvered to gather and reflect sound
towards their ears.
April 6-10, 2020 4Diffraction of Sound Waves
Diffraction involves a change in direction of waves as they pass through an opening or
around a barrier in their path. Water waves can travel around corners, around obstacles and
through openings. The amount of diffraction (the sharpness of the bending) increases with
increasing wavelength and decreases with decreasing wavelength. In fact, when the
wavelength of the wave is smaller than the obstacle or opening, no noticeable diffraction
occurs.
Diffraction of sound waves is commonly observed; we notice sound diffracting around corners
or through door openings, allowing us to hear others who are speaking to us from adjacent
rooms. Many forest-dwelling birds take advantage of the diffractive ability of long-wavelength
sound waves. Owls for instance can communicate across long distances since their long-
wavelength hoots are able to diffract around forest trees and carry farther than the short-
wavelength tweets of songbirds. Low-pitched (long wavelength) sounds always carry further
than high-pitched (short wavelength) sounds.
Refraction of Sound Waves
Refraction of waves involves a change in the direction of waves as they pass from one space
to another. Refraction, or bending of the path of the waves, is accompanied by a change in
speed and wavelength of the waves. So, if the space (or its properties) are changed, the
speed of the wave is changed. Thus, waves passing from one space to another will undergo
refraction. Refraction of sound waves is most evident in situations in which the sound wave
passes through a space with gradually varying properties.
The following diagrams are visual representations of wave behaviors. Label the diagrams
below as diffraction, reflection or refraction.
A. B. C.
______________ ______________ ______________
Write a summary paragraph based on the information from the article.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
April 6-10, 2020 5DAY 4
Seeing Color
https://www.youtube.com/watch?v=9Vsl0Iom3S0
https://www.pantone.com/color-intelligence/articles/technical/how-do-we-see-color
How do we see Colors?
A
B C
D What term best describes the diagram at
the positions labeled above?
E
A. ________________________
B. ________________________
C. ________________________
D. ________________________
E. ________________________
April 6-10, 2020 6DAY 5
Sound Waves vs. Light Waves
https://www.youtube.com/watch?v=cS6L4NEBw4w
https://www.youtube.com/watch?v=iI96iZ8SH4o
Use the Venn diagram below to appropriately identify the similarities and differences between
sound and light waves.
LIGHT WAVES SOUND WAVES
BOTH
April 6-10, 2020 7You can also read
