GA Milestones Science Study guide 8th
grade- Questions and Answers
Reflection Reflection occurs when a wave strikes an object or surface and bounces off. A
echo is reflected sound. Sound reflects from all surfaces.
Ex: Walls, floor, ceiling, furniture, and people
You see your face in a mirror because of reflection. Light waves produced by a source of light
such as the sun or a light bulb bounce off your face, strike the mirror, and reflect back to your
eyes.
However when light reflects from an uneven surface, you can't see a sharp image because the
reflected light scatters in many directions.
Refaction A wave changes direction when it reflects from a surface. Waves can also
change directions in another way.
Ex: You are swimming and you try to grab a sinking object, but you miss You missed grabbing
the object because the light rays from the object changed direction as they passed from water into
the air.
The bending of a wave as it moves from medium to another is called refaction
Refraction and Wave Speed The speed of a wave can be different in different materials.
Ex: Light waves travel faster in air than in water
, Refraction occurs when the speed of a wave changes as it passes from substance to another.
A line that is perpendicular to the water's surface is called a normal. When a light ray passes
from air into water, it slows down and bends toward the normal. The larger the change in speed
of the light wave is, the larger the change in direction is.
Refraction and Color Sunlight contains light of various wavelengths. When sunlight
passes through a prism, refraction occurs twice: Once when sunlight enters the prism and again
when it leaves te prism and returns to the air.
Violet light has the shortest wavelength and is bent the most.
Red light has the longest wavelength and is bent the least.
Each color has a different wavelength and is reflected a different amount. As a result the colors
of sunlight are separated when they emerge from the prism.
Diffraction Why can you hear music from the band room when you are down the hall?
You can hear the music because the sound waves bend as they pass through an open doorway.
This bending is caused by diffraction, which is the bending of sound waves around a barrier.
Light waves can diffract, too. You can hear your friends in the band room before you can see
them, there fore, you know light waves do not diffract as much as sound waves do.
Diffraction and Wavelength The reason that light waves don't diffract much when they
pass through an open door is that the wavelengths of visible light are much smaller then the
width of the door.
grade- Questions and Answers
Reflection Reflection occurs when a wave strikes an object or surface and bounces off. A
echo is reflected sound. Sound reflects from all surfaces.
Ex: Walls, floor, ceiling, furniture, and people
You see your face in a mirror because of reflection. Light waves produced by a source of light
such as the sun or a light bulb bounce off your face, strike the mirror, and reflect back to your
eyes.
However when light reflects from an uneven surface, you can't see a sharp image because the
reflected light scatters in many directions.
Refaction A wave changes direction when it reflects from a surface. Waves can also
change directions in another way.
Ex: You are swimming and you try to grab a sinking object, but you miss You missed grabbing
the object because the light rays from the object changed direction as they passed from water into
the air.
The bending of a wave as it moves from medium to another is called refaction
Refraction and Wave Speed The speed of a wave can be different in different materials.
Ex: Light waves travel faster in air than in water
, Refraction occurs when the speed of a wave changes as it passes from substance to another.
A line that is perpendicular to the water's surface is called a normal. When a light ray passes
from air into water, it slows down and bends toward the normal. The larger the change in speed
of the light wave is, the larger the change in direction is.
Refraction and Color Sunlight contains light of various wavelengths. When sunlight
passes through a prism, refraction occurs twice: Once when sunlight enters the prism and again
when it leaves te prism and returns to the air.
Violet light has the shortest wavelength and is bent the most.
Red light has the longest wavelength and is bent the least.
Each color has a different wavelength and is reflected a different amount. As a result the colors
of sunlight are separated when they emerge from the prism.
Diffraction Why can you hear music from the band room when you are down the hall?
You can hear the music because the sound waves bend as they pass through an open doorway.
This bending is caused by diffraction, which is the bending of sound waves around a barrier.
Light waves can diffract, too. You can hear your friends in the band room before you can see
them, there fore, you know light waves do not diffract as much as sound waves do.
Diffraction and Wavelength The reason that light waves don't diffract much when they
pass through an open door is that the wavelengths of visible light are much smaller then the
width of the door.
