مراجعة هيكل امتحان العلوم انسباير الصف الثامن الفصل الثاني
محتوى الموضوع
هدا الملف ل الصف الثامن لمادة علوم الصف الثامن الفصل الثاني
مراجعة هيكل امتحان العلوم انسباير الصف الثامن الفصل الثاني
Transferring charge
Charged particles transfer between two conductors is called transferring charge by conduction
As shown in the figure above Charged particles flow from the object with a greater concentration of negative charge to the object with a lower concentration. Similar to water flowing from a container with higher water level to a container with a lower level
The flow Of charged particles continues until the concentration Of charge on both objects is equal
Conservation Of charge
Notice that the amount of water didn’t change. The amount of water that started in the full container is the same as the amount of water after the two containers become equal, This is similar to the charged particles flowing between the two conductive objects
Which statement explains why the socks cling to the blanket
A) The socks and blanket dried together which caused them to cling to each other
B) The socks and blanket are conductors that picked up some positive charges that keep the clothes together
C) The socks and blanket are insulators that picked up some negative charges that keep the clothes together,
D) The clothes picked up opposite charges. The opposite charges are attracted to each other
Which solution would reduce this problem in a dryer
A) crinkled- up ball of aluminum foil will conduct the charges and remove the charges from the clothes
B) Place less clothes in the dryer to prevent rubbing
C) Lower the electricity the dryer uses to lower the number of charges in the dryer
D) Dry clothes without them touching so that the clothes do not dry together
Lesson 3: Simple Circuit
1. A source Of electric energy “battery”
2. An electric device “light bulb”
3. An electric conductor “wire”
4. A switch “on, Off”
2) Absorption
Is the transfer Of energy by a wave to the medium through which it travels
The amount of energy absorbed depends on
• The type Of wave
• The material in which it moves
In the figure on the right the sound from the cell phone is absorbed by the insulation in the wall
3) Transmission
Is the passage Of a wave through a medium. The sound from a cell phone in the figure on the right transmits easily through an uninsulated wall
Without transmission we would not hear sound waves on the Other side of doors
Speed of Sound
Two factors that influence the speed of sound waves are
1. The density
2. The temperature of the medium
Gas particles are far apart and collide less Often than particles in a liquid or a solid. As shown in the table on the right, a gas takes longer to transfer sound energy between particles. In a solid where the particles are packed very close together, the particles collide and transfer energy very quickly. The more dense medium, the faster sound will travel through it
Temperature
Particles move faster and collide more Often as the temperature Of a gas increases. This increase in the number Of collisions transfers more energy in less time. Temperature has the opposite effect on liquids and solids. As liquids and solids cool, the molecules move closer together. They collide more often and transfer energy faster
In liquids and solids, increasing temperature
decreasing the speed of Sound
You are in a sound -proofed hallway. Someone standing around the corner from you speaks and you hear them. Which claim offers the best evidence and reasoning for this phenomenon
A) Sound is not affected by types of materials, because sound can travel though solids, liquids, and gases
B) Sound waves are absorbed by the sound- proofed walls and then transmitted through the wall to your ear
C) Sound waves diffract so even though the walls do not reflect the sound wave, the sound wave can still travel to your ear
D) Sound -proof walls allow sound waves to reflect all of the sound that is directed toward them. So, the sound must bounce off them and go to your ear
Questions
This is the term that describes when light passes through matter
A) Transmission
B) Transparent
C) Translucent
D) Opaque
Which Of the following is NOT a cause Of a wave changing direction
A) Reflection
B) Transmission
C) Radiation
D) Absorption
When a wave bends or spreads past a medium, this is referred to as
A) Reflection
B) Refraction
C) Radiation
D) Diffraction
4) Sound travels faster in
A) solids
B) gas
C) water
D) air
Movie theaters use sound proofing to reduce echoes, Soundproofing materials are designed to the sound
A) Absorption
B) Transmission
C) Diffraction
D) Reflection
Which Of the following is NOT a way that waves interact with matter
A) Waves can be reflected by matter
D) As waves pass through matter, some Of the energy they carry can be transferred to matter
7) Which type Of interaction is this
A) reflection
B) refraction
C) diffraction
8) Which type Of interaction is this
A) reflection
B) refraction
C) diffraction
A) Waves can be reflected by matter
B) Waves are affected by gravity
C) Waves can transfer energy to the medium through which it travels
B) refraction
Which type Of interaction is this
reflection
diffraction
Which type Of interaction is this
reflection
refraction
diffraction
Sound travels FASTEST through which of these materials
A) Air
B) Empty space
C) solid
D) Water
Sound does not travel in space because
A) Space is too far away
B) There is no matter in space
C) The energy is too weak
D) The sound from our surrounding id too
Why is the school library covered with carpet
So, everyone can make a lot of noise to help absorb sounds to keep it quiet because it looks good to help absorb sounds so it can stay noisy The image represents which of the following wave interations
Reflection
Absorption
Transmission
Diffraction
What pattern best describes the relationship between wavelength and frequency
A. As frequency increases, wavelength increases
B. As frequency decreases, wavelength decreases
C. As frequency increases, wavelength decreases
D. There is no relationship between wavelength and frequency
Read the passage and then answer question
Stars and other objects in the universe give Off, or emit, energy in the form Of waves Most stars emit energy in all wavelengths. But how much Of each wavelength they emit depends on their temperatures. Hot stars emit mostly shorter waves with higher energy, such as X-rays, gamma rays, and ultraviolet waves. Cool Stars emit mostly longer waves with lower energy, such as infrared waves and radio waves. The Sun has a medium temperature range. It emits much Of its energy as visible light. These waves travel through vast regions of space and reach Earth
Which argument is best supported by the passage
The higher the temperature Of a Star, the more energy it emits
B. Cool stars do not produce radio waves
C. Visible light only comes from the Sun
D. The amplitude of a light wave is determined by its energy
Lesson 2: Reflection and mirrors
What happens when light reflects off a surface
Reflection of Light
When you look at a pane of glass, you sometimes can see an image of yourself. Light bounces off you, strikes the glass, and bounces back to your eye. Think about a calm lake like the one on the right. You can see the reflection of the trees on the other side of the lake
Law of Reflection
Light behaves in predictable ways when it reflects The rays in the ray diagram show how light reflects imaginarv line perpendicular to a reflecting surface is called the normal. The light ray moving toward the surface is the incident ray. The light ray moving away is the reflected r.y
law of reflection, when a wave is reflected from a surface, the angle of reflection is equal to the angle of incidence
An image that you can see, but does not really exist is called which of the following
A) Real Image
B) Fake Image
C) Virtual Image
D) Digital Image
4) a real image
A) is produced by virtual rays and can be projected on a screen
B) is produced by real rays and cannot be projected on a screen
C) is produced by virtual images and cannot be projected on a screen
D) is produced by real rays and can be projected on a screen
5) Convex lenses can produce
A) Real, erect images
B) Virtual, inverted images
C) Real, inverted images
D) no images form
6) Which describes a convex lens
A) triangular in shape
B) more transparent in the middle
C) thicker on the edges than in the middle
D) thicker in the middle than on the edges
Which lens is used to magnify objects and refract light. This type Of lens is curved outward
A) convex
B) concave
is a lens that is thicker in the middle and makes an object appear bigger
A) prism
B) convex lens
C) concave lens
D) mirror
is a lens that is thicker on its edges and makes an Object appear smaller
A) mirror
B) convex lens
C) concave lens
D) prism
What Does a Concave Lens DO
Make things bigger
Make things smaller
Make things closer
Make things happy
What Does a Convex Lens DO
Make things bigger
Make things smaller