22/01/2023
مراجعة ساينس للثالث الاعدادي
اسئلة هامة
Give reasons for:
The moving car with a certain speed seems to be at rest to the moving observer with the same speed and the same direction.
Cars are provided with speedometer.
The amount of consumed fuel by a plane flies between two cities differs according to the wind direction.
The body that moves by constant uniform speed has acceleration equals zero.
A moving object whose its final position is the same as the primary position, its value of velocity is equal to zero.
It is difficult to obtain constant speed practically.
The image formed by a plane mirror is always virtual.
The convex mirror is placed to the left side of the car's driver.
Short-sighted person sees the far objects distorted.
No image is formed when the object is placed at the focus of a convex lens.
The lens has two focus, while spherical mirror has one focus.
The concave mirrors are used in hair dresser's shop.
A convex mirror is put at the left side of the driver of the car.
The explosion of some stars suddenly.
The mitosis division plays an important role in the multicellular organism’s life.
The mitotic division is important for children.
Before starting division, the cell passes through interphase.
Mitosis is important for child body.
Interphase comes before cell division.
Asexual reproduction maintains the genetic structure of the living organisms.
Meiotic division is called reduction division.
Sexual reproduction is a source of genetic variation between individuals.
Sexual reproduction is a source of the genetic variation.
The object which moves with a regular speed the value of its acceleration equals zero.
What happen
Person suffers from short-sightedness and use glasses of concave lens.
A body is placed Infront of convex mirror.
Rupturing of the sporangium of bread mold fungus.
Rupturing the walls of sporangia in the bread mould fungi.
The incident light ray passes through the center of curvature of the concave mirror.
Putting a yeast fungus in a warm sugary solution.
When the fusion of male gamete with the female gamete.
Putting an object in front of a convex lens at its focus.
Starfish losses one of its arms, while it contains a part of the central disc.
A light ray is incident by an incidence angle 35° on a plane mirror.
An amoeba cell divided into three successive mitotic divisions.
The bud in the yeast fungus is remain connected to the parent cell.
A body is decelerating.
An incident light ray passes through the optical center of a lens.
The movement of galaxies apart.
Putting a yeast fungus in a warmed sugary solution.
The real speed of a moving object is equal to its relative speed.
When do the following cases occur... !
The distance covered by a body equals the amount of its displacement.
Reflection of light ray falls on spherical mirror of itself.
The incident light ray passes through the lens without refraction.
Disappearance of the parent cell when it produces new individuals.
The light bouncing off in the same medium.
Duplicating the amount of genetic material (DNA) in the cell which prepares for division.
The distance is equal to the amount of displacement.
The incident light ray falls on a spherical mirror reflects back on itself.
The distance covered by a body equals the amount of displacement happened.
What are the results of ...?
Decreasing the speed of an object as time passes with reference to acceleration.
The presence of the attraction force of the Sun according to Fred Hoyle assumptions.
The movement of an object where it completes one circulation with reference to displacement.
The nebula lost its heat as time passes according to Laplace assumptions.
Absence of centrosome in the animal cell.
A light ray passes through the optical center of the lens.
Combination of the male gamete and female gamete.
Less convexity of the eye lens surfaces.
when we placing a plane mirror to the right and left of the driver instead of the convex mirror.
Light ray passes through the optical center of the lens.
If the gravity between the Sun and planets which rotate around is vanished.
Write the number which refers to:
The length of image which is formed to an object its length 4 cm at distance equals the double of focal length of concave mirror.
The radius of spherical mirror its focal length equals 5 cm.
The number of galaxies in the universe.
The ratio of helium gas in the universe within minutes of Big Bang.
The number of cells resulting from the division of a somatic cell three successive times.
The speed of a car covering a distance of 1200 meters in a half minute.
The relative speed of an observer moving in the same direction with the same speed of the object.
The distance between a person and his image in a plane mirror, when he stands at a distance of 2 meters from it.
The number of cells resulting from the division of a somatic cell three successive times.
The speed of a car covering a distance of 1200 meters in a half minute.
The relative speed of an observer moving in the same direction with the same speed of the object.
The distance between a person and his image in a plane mirror, when he stands at a distance of 2 meters from it.
The length of image which is formed to an object its length 4 cm at distance equals the double of focal length of concave mirror.
The radius of spherical mirror its focal length equals 5 cm.
The number of galaxies in the universe.
The ratio of helium gas in the universe within minutes of Big Bang.
Write the mathematical relation between:
the angle of incidence and the angle of reflection.
the radius of mirror curvature and its focal length.
Complete the following statements:
The concept of .......... is linked to the change of an object's position as time passes
according to a fixed position.
In flowering plants, a cell division occurs in the anther to produce.
The solar system is located in one of the spiral arms of the.......... galaxy.
The ..........mirror whose reflecting surface is a part of the outer surface of the sphere.
The change in the position of an object as time passes according to the position of another object is called ……
The convex mirror, whose reflecting surface is a part of the........... surface of the sphere. ........... is considered one of the fastest wild animals, where its speed is 27 m/s.
The object is put at a distance........ the focal length of the convex lens, the formed image is virtual, upright and enlarged.
If the objects speed increases at a rate, then in this case the movement is described as..........
The formed image of an object by the plane mirror is to the object. reversed, and equal ……
Increasing in the convexity of eye lens surfaces leads to…….
In the interphase during the cell division duplicates……
An object put Infront of a concave mirror between the focus and the centre of the mirror curvature, so the properties of the formed image is ….
There is no part of the central disc with the missing arm, in the starfish leads to……
The spherical mirror that can be used in making solar ovens for cooking food is the ……
Hydra reproduces by........
The increase of the eye lens convexity leads to its focal length.
........... is the site of connection of the two filaments that form the chromosome.
Correcting long-sightedness by using........... lens and correcting short-sightedness by using............ lens. The spindle fibers are formed during the cell division in the phase and disappear in the ............ phase.
Acceleration is.......... physical quantity and the mass is. physical quantity.
In the animal cell, the spindle fibers are formed by .........., while in plant cell the spindle fibers are formed by …….
If an object of 3 cm length was put at a distance of 4 cm from a concave mirror its focal length is 2 cm, so the length of the formed image is …..
In human and animal, meiosis division occurs in ….. to produce male gametes.
The ratio between the object length and the formed image length by a concave lens …… whole one.
If the number of chromosomes in a nucleus of a maize pollen grain is 10 chromosomes, then the number of chromosomes in each nucleus of stem cell of the same plant is ….. chromosomes.
Mass is considered from……. physical quantities.
The image that can be received on a screen is called image. 3. When an object speed decreases by passing time, then it moves at …. acceleration.
The incident light ray which is parallel to the principal axis of a concave mirror reflects passing through……
The time is considered one of physical quantities.
The real image is not formed by using........ mirror or plane mirror.
The vision defect which is due to the decrease of convexity of the eye lens surface is called...........
If the object at rest moves regularly until its speed reaches 12 m/sec. after 3 seconds, so its acceleration equals
The position of the centre of curvature of the convex mirror is…… the reflecting surface.
…….. reproduction occurs in most higher living organisms.
When a body starts its movement from rest, its initial speed is ……
The solar system is located in …… galaxy.
The Sun takes about 220 million years to complete one rotation around the centre …….
The.......... telescope was launched in April 1990 and it rotates around the Earth at a height of 500 km.
When an object with 15 cm. length is placed at a distance 6 cm. from a concave mirror its focal length is 3 cm., therefore the length of the formed image is
If the number of chromosomes in the pollen grain of a plant is 8 chromosomes, then the number of chromosomes in the leaf cell of this plant is…..
............is a disease leads to formation of the image behind the retina.
The incident light ray with an angle 40° on a plane mirror it reflected by an angle
When object covers equal distances in equal periods of time, it moves with........... speed.
When two cars moves in opposite direction with speed 100 km/h. for each so the speed of the second car as estimated by the driver of the first car..........
1. The acceleration of an object is ...... if its speed increases as time passes.
2. Spherical mirror has one........... axis.
3. The distance covered at a certain direction is..... and it is a vector physical quantity.
4. The image can be received on a screen.
1. If an object starts its movement from rest, it means that its initial speed equals
2. Our solar system is located in one of the.......... arms of the Milky Way galaxy.
3. At the end of ., the nucleolus and the nuclear membrane disappear at the mitosis.
The chromosome consists of two connected threads at the
1. Force is considered a...... physical quantity, and mass is considered a.... physical quantity.
2. If the object's velocity decreases with time, the acceleration is called
3. A virtual, magnified and erect image can be obtained by mirror or lens.
4. The secondary axis of the spherical mirror is any straight line passing by point on its surface except......... of the mirror. and any
1. The two factors necessary for the movement description are
2. Displacement from .....And .....physical quantities and is measured by
3. Focal length of concave mirror equals the distance between............ and ......
4. ....... lens collects the light rays and........... lens diverges the light rays.
Write scientific terms:
Unit 1
The length of the shortest straight line between two positions
The speed by which the object moves to cover equal distances at unequal periods of time.
A speed of the moving object relative to a fixed or a moving observer.
The length of the shortest straight line between two positions.
The value of change of an object's speed in one second.
The regular speed by which the object moves to cover the same distance at the same period of time.
The body that its position doesn't change as the time passes.
A vector quantity that equals the amount of displacement covered by the object in one second.
The speed of moving body related to a moving or a fixed observer.
Change the position of an object with the time related to a fixed point.
The displacement covered in a unit time.
Decreasing the speed of a moving object by constant rate until it stops.
The value of change in the object speed in one second.
The rate of change of the distance.
Displacement in one second.
It is the speed at which the object moves to cover equal distances at unequal periods of times.
It is the actual length of the path that a moving object takes from the starting point of the movement to the end point.
The speed of the moving object relative to a static or a moving observer.
The displacement covered in one second.
The displacement per unit time.
A mathematical method used by physicists to predict the relation between certain physical quantities.
Calculate the value of acceleration when the object speed changes from 6 m/sec to 12 m/sec through 3 sec.
The speed of a moving object relative to a standing or a moving observer.
Unit 2
The lens that is used to treat a person who can't see the near objects clearly.
The straight line that passes through the pole of the mirror and its centre of curvature.
The straight line that passes by the centre of curvature of the mirror and any point on its surface except the pole.
The bouncing off the light ray to the same side when it strikes a reflecting surface.
The distance between the focus of the concave mirror and its pole.
A disease that causes a difficulty of vision as a result of the darkness of the eye lens.
A vision defect caused due to the formation of an image behind the eye retina.
One of the vision defects that leads to the formation of images behind the eye retina.
The point that is in the middle of the reflecting surface of the spherical mirror.
The centre of the sphere where the lens's face is a part of it.
Unit 3
It contains all the galaxies, stars and planets.
A theory that explains the origin of the universe due to a great explosion science 15000 million years.
The unit that is used to measure the distance between the celestial bodies.
Arrangement, harmony and distinctive shapes of the groups of stars in the universe.
The planet of life.
A flat gaseous round disk that formed the solar system according to Laplace assumptions.
Unit 4
A process that contributes in genes exchanging between the two homologous chromosome's chromatids and distributing them in the gametes.
The combination of the male gamete and female gamete to form a zygote.
A type of asexual reproduction takes place in plants by their different vegetative organs except seeds.
The part which is responsible for splits lengthwise of chromosomes into two poles of the cell during anaphase.
A type of asexual reproduction that takes place in plants by different vegetative organs without the need of seeds.
A type of reproduction that takes place by only one parent, without producing gametes.
The point of connection of two chromatids of the chromosome together.
The type of asexual reproduction that occur in multicellular organisms such as hydra, and in unicellular organisms such as yeast fungus.
The ability of some living organisms to reproduce by compensating their missing parts.
The fusion between two different types of reproductive cells of one species of living organism to produce the zygote.
The value of change of an object's speed in one second.
Special organs for reproduction in algae and fungi.
Change of an object position as time passes according to the position of another object.
A biological process, where the living organism produces new individuals of the same kind and thus, ensuring its continuity.
A dangerous disease occurs when some of the body cells are divided continuously without controlling.
The process of exchange of genes between the two inner chromatids of the tetrad and distributing them randomly in the gametes.
The point at which the two chromatids are joined together.
It is the point of connection of the two chromatids of the chromosomes.
Thread like bodies present in cells' nuclei and they represent the genetic material of the living organisms.
A process in which genes exchange between the two inner chromatids of the tetrad.
Cellular division which leads to the formation of gametes.
A phase in which a series of adverse changes occur, ends with forming two cells, each cell has the same number of chromosomes of the mother cell.
A group of four chromatids formed when two chromosomes are arranged in homologous pairs in the meiotic division.
A type of asexual reproduction that occurs in simple algae and bacteria.
The process through the inner chromatids of tetrad are exchanged during meiotic division.
The ability of some animals to compensate their missing parts.
Problems
Calculate the value of acceleration when the object speed changes from 6 m/sec to 12 m/sec through 3 sec.
An object moves in a straight line at a speed of 4 m/s in a certain direction, its speed reaches 20 m/s through 4 seconds. Calculate the acceleration of the moving object, mention its type.
An object starts to move from rest at an acceleration equals 4 m/s² during 6 seconds. Calculate the final speed of this object.
A car, its relative speed is 80 km/h. Calculate its actual speed in the following cases:
1. When the observer is at rest?
2. When the observer moves in the same direction of the car with speed 30 km/h?
A car moves from rest, then its speed increases to be 20 m/sec through 8 seconds - calculate the acceleration by which the car moves.
An object was put in front of the reflecting surface of a vertical plane mirror. the distance between the object and its image in this mirror was (5 meters). If the mirror is moved a distance, So that the distance between the object and its image became (4 meters). Determine the distance that moved by the mirror and its direction related to the object?
An o**m of an animal contains 16 chromosomes determine each of the following: 1. Number of chromosomes in the liver cell of this animal.
2. Number of chromosomes in the s***m that produced by the male of this animal.
A car moves at speed 80 m/sec. if the driver used the brakes the speed decreases by 2 m/sec each one second. Calculate its speed after 12 seconds from using the brakes.
Calculate the actual speed of the car, whose relative speed is 130 km/h relative to an observer moving in the same direction at a speed of 50 km/h.
A runner covered a distance of 300 meters in 30 seconds, then he returned back walking to the start point in 170 seconds. Calculate the average speed of his complete trip.
Rubber ball falls from a height of 8 meters then rebounds from the ground to upward a distance of 4 meters then falls down 4 meters to rest on ground calculate :
1. The distance covered.
2. Displacement.
An object was placed at a distance of 8 cm from the optical centre of a lens then a real diminished image was formed for the object, and when the object was moved 4 cm. towards the lens a real equal image was formed for the object.
1. Calculate the focal length of the lens.
2. Draw the path of the rays that formed the image when the object was at a distance of 4 cm from the optical centre of the lens.
An object is placed opposite to a concave mirror at a distance 6 cm. equal the double of its focal length. Determine the position and properties of the image formed by drawing.
A regular speed car covered 80 meters in 4 seconds then decelerated and stopped after 4 seconds. Calculate acceleration value:
1. In the first 80 meters.
2. Since beginning deceleration.
When division of two cells occur, the first one is of human skin and the other of human o***y. Mention:
1. The type of division in each cell.
2. Number of cells formed after division.
- grasses.
A car moved at 15 m/sec, and when the driver applied the brakes to reduce the speed, the speed decreased to 10 m/sec within 2 seconds. Calculate the required time to stop the car from the moment of pressing the brakes, if the car is moving with uniform acceleration.
A bike moves from the rest and its speed reaches 5 m/sec. in 2.5 sec. while the speed of a car increases from 20 m/sec. to 45 m/sec. at the same time. Which of them moved at a greater acceleration ?
A racer covered 30 meters northward within 10 seconds then 60 meters eastward within 20 seconds then 30 meters southward within 10 seconds and then returns back to the start point within 20 seconds.
1. What is the average speed of the racer?
2. What is the velocity of that racer?
Through 2.5 second the velocity of a car increases from 20 m/s to 25 m/s, while a bicycle starts its motion from rest and its velocity reaches to 5 m/s in the same period of time, which of them (car or bicycle) gain larger acceleration.
A train moves with uniform speed (regular speed) equals 90 km/h. Calculate the distance which was covered by this train during 20 seconds.
Show by drawing
Show by drawing the path of rays that form an image of an object that is placed at
a distance greater than the radius of curvature of a concave mirror. Mention the properties of the formed image.
Show by drawing only with complete labels the pathway of the emitting light rays from an object placed at the focus of convex lens.
Show by drawing, the formation of an image in the form of light spot by convex lens? then mention the position of the object?
Show by drawing meiosis division and the formation of gametes ?
Illustrate with drawing the formed image by convex lens, when the body at a distance
greater than double the focal length, then mention the properties of the formed image.
Mention the position and characteristics of the image formed by a convex lens for an object placed at a distance larger than its focal length and less than double its focal length, explain your answer with drawing.
Determine the type of the cell division that is needed to carry out each process of the following:
The process of exchange parts of the inner chromatids of the tetrad.
Vegetative reproduction in plants.
Which of the following two images is real and which of them is virtual ?
1. An image of a child standing in front of a convex mirror.
2. An image of a far object that can be received on a screen.
According to the Big Bang theory, rearrange the following events from the oldest to the nearest:
1. The Sun was born then the Earth and planets were created.
2. Earliest life forms began to appear on Earth.
3. Matter got joined in masses.
Put (✔) or (x) in front of the following statements:
The light ray falls parallel to the principal axis of a convex lens, it emerges from it passing by its centre.
The Sun and the group of planets around which it revolves are called Milky Way.
Crossing over is the source of genetic variation between members of the same species.
Convex lenses are used in manufacture of solar ovens.
Contact lenses are placed directly on the cornea of the eye, and can be removed easily.
The cell prepares for division during interphase by reducing its genetic material.
When a plane flies in the opposite direction of the wind, its velocity decreases, and therefore the amount of the fuel consumed decreases.
During the anaphase of mitosis cell division, the centromere of each chromosome splits lengthwise into two halves.
The image which is formed by plane mirror is real image.
A concave mirrors are placed at right and left sides of car driver.
The cells resulted from meiotic division contain half the genetic material of the parent cell.
The offspring resulted from asexual reproduction have new genetic traits different from their parents.
The relative speed is the speed of an object relative to a static or moving observer.
The scientist Moulton published a research entitled "world order".
Most of the information of astronomers about the Sun came from the study of its shape.
If a car covers a distance of 500 m in 25 sec. with uniform speed, its speed will be 20 m/s.
Determine the type of
the optical piece (lens of mirror) then mention its type
(convex - concave - plane) when it is able to: 1. From a virtual upright image equal to the object in size.
2. From a virtual upright enlarged image on the other side of the optical piece.
Explain how the followings happen:
1. The object moves with a non-uniform speed.
2. Forming of the zygote.
3. Obtaining a virtual (laterally inverted) reversed image.
Collecting photos for locations and events took
place millions of years ago.
Explain the importance of the followings:
Reproduction.
The concave lens.
The solar telescope.
Velocity of winds on pilots flights.
Golden Nano technological molecules.
The contact lenses.
The anther in the flowering plants.
A convex mirror at the left side of the driver of the car.
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