Download The advantages of frictions

1
Friction force :
It is the amount of force that exists between two surfaces and affects the
movement in the opposite direction.
Friction occurs between two surfaces when one of them touches the other, the
friction force is always in the opposite direction of the moving objects.
Examples : (activities)
a- sandy floor
1- Friction between a small rubber ball when it rolls on :
b- smooth floor
2- Ride a bike and push its pedal, then stop pedaling during the movement of
the bike.
3- Friction force between plastic cube and :
a- sloping wooden board.
b- Increase slop of the wooden board.
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From the previous activities we conclude that :
1- Friction force arises when two surfaces touch each other.
2- When friction force is larger than the movement force the body doesn’t
move.
3- When the friction force is smaller than the movement force, the body
moves.
4- The direction of the friction force is opposite to the direction of the
movement.
The factors affecting the friction force :
1- The surface area of the moving object: by increasing the surface area of
the moving object the friction force increase and vice versa 50 there is a
direct relation between the surface area of the moving object and the
friction force.
2- The type of the material surface : The friction force increases between
rough surfaces and decreases between smooth surfaces.
3- The speed of the body : by increasing the speed of the body, the friction
force increases.
The disadvantage of friction :
Friction causes damage to most of machines.
Because it raises the temperature of the internal moving parts of the machines
to more than a certain extent, so machines are damaged.
Ways to decrease the friction force :
1- Using Lubricants and Oil.
2- Using ball bearings which have smooth surfaces, so the friction force
between them is almost non-existent.
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Questions on Unit One
lesson One
Q1 Write the scientific term:
1. The force that slows down the object motion & has its effect in the
opposite direction of the object's movement.
(
)
2. It damages the internal parts of the machines.
(
)
3. They form a thin layer between the internal surfaces of the
machines parts so it decreases the friction force.
(
)
4. A group of small metal balls which have smooth surfaces to prevent
the friction force between them.
(
)
Q2 Correct the underlined word:
1. The friction force is always in the same direction of the object's
movement.
2 . Lubricants& oils are used to increase the effect of the friction
force.
3. The ball bearings are formed of a group of small metal balls which
have rough surfaces to prevent the friction force.
Q3 Complete:
1. The force that slows down the object's motion is called…………………..
2.The friction force has its effect on the……………………….direction of the
object's movement.
3. ……………………is used to decrease the effect of the friction force
between the internal moving parts of machines.
4. The disadvantage of the friction force
is:…………………………………………………………………………………………..
Q4 Mention the ways that can be used to decrease the
disadvantage of the friction force:
1. ---------------------------------------------------------------2. ---------------------------------------------------------------Give reasons: Using lubricants& oils in car engine.
-------------------------------------------------------------------
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1- The friction between solid object and air :
Air resistance : It is the friction force resulting from the movement of solid
objects through air.
Factors affecting the air resistance :
1- The speed or velocity of the body by increasing the speed of the body
that moves through air. Air resistance increases.
Life application :
You shouldn’t increase the car speed to a certain limit to reduce the air
resistance and consumption of fuel.
2- The surface area :
By increasing the surface area of the body that moves through air, air resistance
increases and vice versa.
Life applications :
1- To decrease air resistance :
a- Rockets, air crafts and rains are designed in streamline shapes.
b- Birds have streamline shapes.
2. To increase air resistance by increasing the surface area.
c- Parachutist opens the parachute to land safely.
d- Birds stretch their wings on lauding.
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2- The friction between solid objects and water :
Water resistance : It is the friction force resulting from the movement of any
object through water.
Factors affecting the water resistance :
1- The speed of the body.
By increasing the speed of the body through water, water resistance increase
and vice versa.
2- The Surface area.
By increasing the surface area of the body that moves through water, water
resistance increases and vice versa.
Life applications :
Ships and fish are streamline shapes.
3- The friction between solid objects:
Factors affecting the friction between two solid objects :
1- By increasing the speed of the moving body.
2- By increasing the surface area of the moving body.
3- Between the rough surfaces.
Life application :
1- Rubber tires
Water on roads reduce the friction between the road and the car tires, so drivers
can’t control the wheels.
The advantages of frictions
1- A car move forward because there is friction between the tires and the
ground.
2- Increase the speed of the car or change of its direction need friction force.
3- Friction between your shoes and the ground prevent your slipping down.
4- Lighting of a match needs friction.
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Questions on Unit One
lesson Two
Q1. Write the scientific term:
1. A type of friction force resulting from object movement on air.
(
)
2. A type of friction force resulting from object movement in water.
(
)
Q2 Correct the underlined word:
1. The moving car is affected by air resistance in the same direction of
its movement.
2. The air resistance decreases when the car moves so fast.
3. The relationship between the area of the object surface exposed to
the air& the air resistance of its movement is an inverse relation.
4. When the parachutist opens his parachute, the friction force
decreases.
5. When the friction force between the air& a car is equal to the force
that moves it, the car moves at a different velocity.
Q3 Give reasons:
1. The fish has a streamline shape.
…………………………………………………………………………………………………….
2. Car drivers should not increase the car speed up to a certain limit.
……………………………………………………………………………………………………
3. Car tires should be replaced when their grooves disappear.
…………………………………………………………………………………………………….
4. Ball bearings decrease the friction between machines internal
moving parts.
…………………………………………………………………………………………………..
5. Rockets, Aircrafts, planes& trains are designed in stream line
shapes.
…………………………………………………………………………………………………
6. The parachutist opens his parachute to land safely.
………………………………………………………………………………………………..
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Q4 Complete:
1. Parachutist opens the parachute to……………………….. the air
resistance & then he…………………….his falling speed so he can lend
safely.
2. The body of the bird has a …………………shape to……………………… the
air resistance (friction force)
3. When the ship or fish move so fast in water,
the………………………….between this objects& water increases.
4. The friction force has its effect on the……………………….direction to
the object's movement.
1.
2.
3.
4.
Q5 Mention the advantages of the friction force:
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Q6 Mention the disadvantages of the friction force.
1. ------------------------------------------------------------2. -------------------------------------------------------------
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The circulatory system consists of the :
1-
Heart.
2-
Blood vessels.
3-
Blood.
Functions of the circulatory system :
- It transports the oxygen and digested food to all body cells, also it
transports the carbon dioxide and other wastes to the excretory system
- It helps to maintain the body healthy.
Circulatory system consists of :
1- Heart.
2- Blood vessels.
3- Blood.
1- The Heart
1- It is a muscular pump.
2- Its size is the size of your fist.
3- It is located in the chest cavity between the lungs.
4- Structure of the heart :
 It consists of four chambers: two atria (right atrium, left atrium) and two
ventricles (right ventricle, left ventricle).
 It consists of 2 sides left side and right side.
 Between the two sides there is a septum to prevent mixing f the blood
from both sides.
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 Between each atrium and ventricle in the same side there is a valve to
allow the blood to pass from atrium to the ventricle and prevents it from
returning back.
2- Blood vessels
They
Arteries
Veins
Blood capillaries
Emerge from the 2 Open in the 2 atria Are the end of the
ventricles of the
of the heart
arteries and
heart
beginning of the
veins
Walls
Function
Thick
They carry the
blood from the
heart to all body
parts
Thin
They carry the
blood from all
body parts to the
heart
Type of the
blood
They carry
oxygenated blood
except pulmonary
artery
They carry deoxy
genated blood
except pulmonary
veins
Example
Aorta
Superior vena cava
inferior vena cava
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Very thin
They deliver food
and O2 to the cells
and then carries
CO2 and waste
product (gas
exchange)
3- The blood
The human blood consists of :
1- Red Blood cells (R.B.C)
a- They are cells without nuclei.
b- Function :
 Carry O2 gas from the lungs to the body cells.
 Carry CO2 gas from the body cells to the lungs.
2- White blood cells (W.B.C) :
a- They are cells with different forms of nuclei.
b- Function : protects the body against the microbes.
3- Blood platelets:
a- They are small fragments of the cells.
b- Function : they form blood clot, so they prevent bleeding from the
wounds.
N.B. Clotting of the blood = coagulation of the blood.
4- Plasma :
a- A yellow watery fluid, the R.B.Cs – W.B.Cs – platelets are floating in it.
Function :
 It carries the digested food to the body cells.
 It carries the wastes from the body cells to the excretory system.
Functions of the blood :
1- Transfer O2 and digested food to the body parts.
2- The defense and protection of the body.
3- Blood distributes and keeps the temperature of the body constant.
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* How to measure your pulse?
Place the first two fingers of the other hand against the wrist near the base of
your thumb.
- The normal average of the pulse = 70 – 80 beats/m.
- The heart beats or cardiac pulse increase during exercising.
Blood circulation
1- Deoxygenated blood
poured into the right atrium of the heart through superior and inferior vena
cava vein.
2- Right atrium contracts pumping the blood to the right ventricle through
valve.
3- Right ventricle contracts pumping the blood to the lungs through pulmonary
artery.
4- Inside the lungs gas exchange occurs and oxygenated blood returns to the left
atrium of the heart through 4 pulmonary veins
5- Left atrium contracts pumping the blood to the left ventricle through valve.
6- Left ventricle contracts pumping the blood to all body parts through aorta
artery.
- The circulation between the heart and lungs is called minor blood
circulation OR pulmonary circulation.
-
The circulation between the heart and other parts of the body is known as
major circulation OR systemic circulation.
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How to maintain the circulatory system?
1- Do physical exercise to strengthen the circulation.
2- Eat balanced food.
3- Avoid eating salty and fatly food.
4- Eat more vegetables and fruits.
5- Drink an appropriate amount of water.
6- Avoid infections and accidents to avoid bleeding.
7- Avoid smoking and smokers.
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Questions on Unit Two
lesson One
Q1 Write the scientific term:
1. The system which transports the digested food, oxygen& water to
all body cells.
(
)
2. A muscular pump which is about your fist in size. (
)
3. It allows the blood to pass from the atrium to the ventricle and
prevents it from returning back.
(
)
Q2 Complete the following:
1. The circulatory system consists of the --------------------------------------&
-----------------------------2. The heart is a muscular ---------------------- which is located at the ----------------------- cavity between the lungs.
3. The heart has four --------------------- which are connected with --------------------------------------Q3 Give reasons:
1. The heart is an important organ.
-----------------------------------------------------------------------------------------2. There is a wall between the right& left side of the heart.
-----------------------------------------------------------------------------------------3. There is a valve between each atrium& ventricle.
-----------------------------------------------------------------------------------------4. The blood flows from atrium to ventricles in one direction only.
----------------------------------------------------------------
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Q4 Label the following:
Q5 Complete:
1. The blood vessels that emerge from the heart are called -----------------------------------------2. The blood vessels that collect the blood from all body parts and
pour it into the heart are called ----------------3. Blood flows inside your body through a network of pipelines called -------------------------4. The ---------------- allow the blood to deliver food& oxygen to the
body cells & carries carbon dioxide and wastes products.
5. The blood consists of --------------------- cells, ---------- cells, -----------------------& -----------------------6. Blood platelets form --------------------- which help in healing wounds.
7. The left ventricle pushes the blood into the ---------8. The ---------------------- blood cells attack the microbes that cause
diseases to human.
9. The ----------------------- blood cells carry oxygen& carbon dioxide
inside the body.
10. The -------------------- atrium receives blood from all body parts
except the lungs.
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Q6 Write the function of:
1. The red blood cell:
-------------------------------------------------------------2. The platelets:
-------------------------------------------------------------3. The white blood cells:
---------------------------------------------------------4. The plasma:
--------------------------------------------------------------5. The blood capillaries:
---------------------------------------------------------------6. The heart:
--------------------------------------------------------------7. The valves:
--------------------------------------------------------------8. The circulatory system:
-----------------------------------------------------------------------------------------Q7 Write scientific term:
1. The two lower chamber of the heart.
(
)
2. The two upper chamber of the heart.
(
)
3. A muscular organ, about the fist size and located within the chest.
(
)
4. The pipelines that extend all over the human body.
(
)
5. The blood circulation between the heart and all body parts except
the lungs.
(
)
6. The cells have no nuclei.
(
)
7. The blood vessels that collect blood from all body parts and pour it
into the heart.
(
)
8. The artery that carries blood rich in carbon dioxide.
(
)
9. The small bodies that play a role in blood coagulation when the
body is wound.
(
)
10. The flow of the blood to the lungs and its returning back again to
the heart.
(
)
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 The digested food absorbed by the blood to the body cells to be burned in
the presence of O2 gas and wastes are produced.
 The undigested food are stored in the large intestine till it is expelled
outside the body as solid wastes (stool)
 The excretory materials : are the waste materials that produced inside the
body cells and the body must get rid of them.
Harmless not used by the body
 Excretory materials :
Harm fullmust get rid of them
Co2 gas is expelled through lungs
 Excretory materials
Excess salts are expelled out in sweat
from the skin
Nitrogen wastes are removed by the
kidneys
How are the wastes enter the blood?
Through the thin walls of nearby capillaries.
Urinary System
Urinary systems consists of :
1- Kidneys : - They are two.
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- They are located on either sides of the backbone.
- They are bean shaped organs
Function : - They filter the blood from urea, uric acid and excess salts
dissolved in water in the form of urine.
2- Ureters : - They 2 tubes connect the kidneys with the urinary bladder.
Function : They carry the urine from the kidneys to the urinary bladder.
3- The urinary bladder : A balloon like sac.
Function : It stores the urine until it is released from the body to the outside
through urethra.
1.1.1.1.1 Skin
It contains sweat glands
Function : Excretory organ.
It excretes the excess salts in the form of sweat.
How to maintain the urinary system healthy?
1- Drink enough amounts of water. (about 2 liters).
2- Eat balanced food low in salt.
3- Avoid schistosomiasis disease (bloody urine) so do not urinate in
irrigation canals.
4- Do not keep urine for long time.
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Questions on Unit Two
lesson Two
Q1 Write scientific term:
1. The undigested food that stored in the large intestine until it passes
out of the body.
(
)
2. The waste materials that produced inside the body cells& the body
gets rid of them.
(
)
3. The organ that gets rid of carbon dioxide gas& water vapour.
(
)
4. The organ that gets rid of nitrogen compounds { Urea& Uric acids}.
(
)
5. The organ which gets rid of the sweat. (
)
6. The system that get rid of urine.
(
)
7. The organ which filters the blood from urea& uric acid in the form
of urine.
(
)
8. Two narrow tubes which carry urine from the kidney to the urinary
bladder.
(
)
9. A balloon like a sac that stores urine until it is released out of the
body through the urethra.
(
)
10. The system which is composed of the kidneys, ureters& urinary
bladder.
(
)
Q2 Write the function of:
1. The Two lungs:
……………………………………………………………………………………………
2. The urinary system:
…………………………………………………………………………………………..
3. The two kidneys:
…………………………………………………………………………………………..
4. The skin:
…………………………………………………………………………………………..
5. The urinary bladder:
……………………………………………………………………………………………
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Q3 Give reason for:
1-The importance of urinary system.
……………………………………………………………………………………………..
2-The kidneys protect us from poisoning.
……………………………………………………………………………………………
3-Presence of sweat glands under the skin.
…………………………………………………………………………………………….
4-You must eat food low in salts.
……………………………………………………………………………………………..
5-You must not urinate or wash in the irrigation canal.
………………………………………………………………………………………………
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Soil :
It is the thin non compacted layer that covers the earth crust.
Soil is made of rocks, it has water, air and humus.
Humus :
It is the decayed remains of plants and animals.
It adds nutrient, to soil.
Importance of soil :
1- Growth of plant, that are important for human and animals.
2- Home for many living organisms.
Soil composed of minerals that resulted from breaking down rocks mixed with
decayed material of dead organisms.
Stages of soil formation :
1- Rocks break down into small pieces with time.
2- Wind breaks down the rocks.
3- Water breaks down the rocks into smaller
pieces.
Fill a graduated tube with water and add to it a
sample of soil
Soil consists of humus, water, mud, silt and gravel
Clay
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How is the soil of Egypt is formed?
1- when the rocks of Ethiopian plateau are exposed for millions years to
wind – heat rain and running water they broken down into small particles.
2- The flood water carried rocks to River Nile then it deposited.
Soil and living things :
- plants need minerals and nutrients in soil to live and grow.
- Animals eat plants that depend on soil.
- Ants and other insects :
Many animals dig tunnels in soil, they make nests and lay their eggs their.
- Animals add nutrients to soil (GR) bec. When they die their bodies decay to
humus.
Top soil layers :
- Root, and animals are in the top layers of soil.
- Roots of plant, take water and nutrients from the soil.
- Roots hold the plant in soil.
- Roots add nutrient to soil.
Lower layers :
- Soil that don’t have much humus.
Rocky layers :
- They contain rocks.
- Earth worms and some spiders make their home underground.
- They dig tunnels in soil allow air, water and nutrients to pass.
- Tunnels helps for growth of plant roots.
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Questions on Unit Three
lesson One
Q1 Complete:
1. The soil contains gravel that produced from breaking down
of……………………………………………
2. The main soil components are ………………………., ……………………..and
……………………………….
3. Humus add nutrients to ……………………………….
4. Water and……………………….. break down rocks into small pieces to
form soil.
5. The origin of the agricultural soil of Egypt is the rocks of
…………………………………..
Q2 Choose:
1. The……………………. is the decayed remains of animals& plants.
{ Humus – Silt – Sand – Clay}
2.The origin of the agricultural soil of Egypt is……………………...plateau.
{ Tibet – Golan – Ethiopian – Red sea}
Q3 Write the function of:
1. The roots of the plant:
.......................................................................................................................................
2.The Earthworm
……………………………………………………………………………………….…………
3-The soil.
………………………………………………………………………………………………….
Q4 Write scientific term:
1.A thin non- compacted layer that covers the earth crust. (
)
2. The remains of the decayed organisms.
(
)
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Q5 Give reason for:
1. The soil is the main components of the environment.
…………………………………………………………………………………………………………
………………………………………………………………………………………………………...
2. Roots of plants are important for soil.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
3. The organisms that live in the soil have a great importance.
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
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Types of soil :
Soil can be classified according to their kind into :
1- Clay soil
2- Sand soil
3- Silt soil
1- Clay soil :
It consists of clay and silt mainly and small amount of sand and humus.
2- Sand soil :
It consists mainly of sand and small amount of clay. Silt and rarely humus.
3- Silt soil :
It composed of a mixture of gravel. Sand clay silt and more humus.
Activity to show the compactness of soil
Add equal amount of water to three samples of clay – sand and silt soil
and expose it to air and sun.
Obs : Sand soil is non compacted (loose – weak)
Clay soil is highly compaceted silt soil is (medium)
Aeration and water absorption
Sand soil is
Well aerated
Clay soil is poorly
Aerated silt soil is medium
Note that :
When the aeration of soil increase the water absorption decrease.
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Drainge of water :
- Sand soil has the greatest draining of
water, clay soil has the lowest silt soil is
medium.
- Clay soil keeps more water than silt that
keeps more water than sand.
Fertility
- According to amount of humus the soil is fertile.
- Silt is highly fertile.
- Clay soil is fertile.
- Sand soil is low fertile.
Comparison between types of soil
Properties
1- composition
Sand
Sand
Clay
Clay and silt
Yellow
Dark
Silt
Mixture of gravel –
clay sand silt humus
Grey
3- size of particles
4- Aeration
Large
Good
Small
Poor
Medium
Medium
5- compactness
6- water absorption
Weak
Low
Hard
High
Medium
Medium
7- drainage of water
8- Holding of water
Fast
Less
Slow
More
Medium
Medium
Less fertile
Fertile
Highly fertile
2- color
9- ferlility
Soil and plants :
1- Sand soil : It is suitable for cultivation plants that produce tubers such as
potato and sweet potats – peanut peanut gives fruits beneath the soil
2- Clay soil : suits the cultivation of cotton, rice, sugar cane wheat and many
vegetable plants.
3- Silt soil : strawberry , lemon, pomegranate and orange.
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Questions on Unit Three
lesson Two
Q1 Complete:
1. The main types of soil are ----------------, --------------- and -------------------------------------------2. The colour of -------------------- soil is dark, while that of --------------------- soil is yellow.
3. The compactness in ---------------------- soil is very weak, while that in
------------------ soil is very high.
4. The ------------------ soil is highly fertile, because it contains a large
amount of ----------------------5. Clay soil keeps (retains) ----------------------- water, while --------------------- soil keeps less water.
6. Silt soil aeration is ----------------------, while clay soil compactness is -------------- and silt soil fertility is----------------------------------------7. Cactus grows in -------------------- soil, while cotton grows in ----------------------------- soil.
Q2 Choose:
1. The size of particles of clay soil is -------------------{ large – small – medium – non of them}
2. The particles of silt soil are ------------- ---- in size.
{ tiny – medium – large – very large }
3. The silt soil compactness is --------------------{ strong – weak – medium - very strong }
4. The aeration of sand soil is ----------------------(good – bad – medium – poor}
5. The sand soil ------------------- water more than the other two types
of soil.
{ drains – retains – keeps – non of them}
6. The most suitable soil for cultivation is the ------{ sand soil – clay soil – silt soil – gravel soil }
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7. Strawberry& Oranges grow in ------------------ soil.
{ sand – clay – silt – clay& sand}
Q3 Write the type of plant which is cultivated in:
1. Sand soil:
………………………………………………………………………………………………
2.Clay soil:
………………………………………………………………………………………………
3.Silt soil.
……………………………………………………………………………………………….
Q4 Write scientific term:
1. The well aerated soil.
(
)
2. The highly fertile soil that contains suitable dissolved salts&
humus.
(
)
3. The soil which is dark& has small sized- particles.(
)
Q5 Give reason for:
1. The water level in clay soil is higher than the water level in both
sand& silt soil.
…………………………………………………………………………………………………………
………………………………………………………………………………………………………...
2. The clay soil is poorly aerated.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
3. The silt soil is highly fertile.
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
Q6 Correct the underlined:
1. The sand soil is strongly compacted, poorly aerated and fertile.
2. The silt soil is poorly aerated.
3. Cactus plant grows in the clay soil.
4. Sweet potatoes grow in silt soil.
5. The clay soil is yellow in color.
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Soil Pollution :
Any change in the environment that disturbs its natural balance and harms its
living organism
Some agricultural soil pollutants :
a- Chemical pesticides :
It leads to : contamination of plants which grow and harms human health and
animals feed on it.
b- Chemical fertilizers :
are used to provide the soil with required elements for plant growth. It leads
to :
1- death of organisms that live in soil.
2- Increase soil fertility.
3- Leaking of these material, to plant that grow in soil harms human and
animals.
C- Industrial wastes :
- They pollute air and water, these pollutants come with irrigation water.
- They increase the acidity of water.
d- increase in soil salinty
- Increase the period between irrigation leads to dry of soil.
- High level of ground water increase of salts.
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* Ways to protect the soil from pollution :
1- Decrease the use of pesticides and depend on natural enemies of
insect.
2- Decrease agricultural fertilizers and use natural fertilizers instead.
3- Improving the drainage of agricultural land.
4- Technology investment in waste water treatment.
5- Making factories for from farmlands.
6- Using technological methods in treatment of factory wastes.
7- Irrigation of agricultural lands regulary to prevent their drying and
increase salts.
8- Promoting environmental awareness among people.
9- Recycle of agricultural wastes to useful materials.
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Questions on Unit Three
Lesson Three
Q1 Complete:
1. The most important soil pollutants are…………………………………,
………………………………………..and……………………………………….
2. The…………………………… is any change in the environment that
disturbs its natural balance.
3. Increasing the periods between irrigation causes
soil…………………………..
4. The materials that cause soil pollution are called……………………….
Q2 Write scientific term:
1. They are chemical compounds which compensate the poor soil with
the elements needed for plant's growth.
(
)
2. They dissolve in irrigation water and rain water forming acidic rains.
3. It prevents the plant growth.
(
)
(
)
4. Any change in the environment that disturbs its natural balance.
(
)
5. Any change in the soil that disturbs its natural balance and harms its
living organisms.
(
)
Q3 Give reason for:
1. Soil pollutants are harmful.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
2. Chemical pesticides are important.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
3. Overusing of Chemical fertilizers is harmful.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
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4. Acidic rains are harmful to the soil.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
5. Soil salinity is harmful to the soil.
…………………………………………………………………………………………………………
………………………………………………………………………………………………………..
6. Farmer must irrigate agricultural soil regularly.
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
Q4 Put (√) or ( x)
1. Adding natural fertilizers to soil leads to soil pollution.
( )
2. Increasing the period between irrigation times leads to increase the
fertility of the soil.
( )
3. Soil pollution causes the disappearance of plants& animals. ( )
4. The pollution is any change in the environment that disturbs its
natural balance.
( )
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Practical sheet – 2nd term
5th prim
Question 1:
- The sample is: oil
- It is used to decrease the friction force.
Question 2:
- The sample is: ball bearings
- It is used to decrease the friction force.
Question 3:
- The sample is: Heart
-
Label the figure.
Question 4:
- The sample is: urinary system
Label the figure.
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Question 5:
- The figure is: soil
- Label the figure
34
Question
- The sample is: …………………..
- It is used to ……………….. the ………………. force.
Question
- The sample is: …………………..
- It is used to ……………….. the ………………. force.
Question
- - The sample is: ……………….
- Label (A) is: …………………
- - Label (B) is: …………………
Question
- - The sample is: ……………….
- Label (A) is: …………………
- Label (B) is: …………………
35
Question
- The sample is: ……………….
- Label (A) is: …………………
- Label (B) is: …………………
36