unit 2 laws of conservation

7/25/2019 unit 2 laws of conservation

1/18

Lesson 2

Conservation of mechanical

energy:

Activity :1

Push a simple pendulum gently then leave it.

Obs:

1. On displacing the pendulum, a work is done,

This work is stored in the form of potential energy.

2. When the pendulum is left:

The potential energy is converted into kinetic energy.

Till it reaches a maximum speed where all of its energy is

converted into kinetic energy.

n of the children swing& theHow much alike are the motio

pendulum?* In both the swing& the pendulum the potential& kinetic energies

without ending.interchangedare

* The sum of the two energies at any moment is constant.

gy:Law of conservation of mechanical ener

The sum of potential& kinetic energies of an object under the effectof gravity is constant.


2/18

Simple electric cell

Activity 2: Lemon& electricity:

* Try to soften the lemon.

* Dip the zinc rod& the copper wire in

the lemon.

* Form an electric circuit near a

compass.

:bs

* The compass deflects indicating the flow of an electric current.

Conc:

* Chemical reactions convert chemical energy into electric

energy..N.B

The electric cell is composed of an acid solution & 2 different metals

dipped in.

Activity: 3

1. Make an electric circuit as in figure:

D2. Close the circuit for one minute.

Obs:

The lamp lights up& becomes warm.Conc:

In the electric lamp, electric energy is converted into light energy&

heat energy.


3/18

Energy transformationtake, several transformations of energy

ar engine

* On operating a

place.

Mention some of these transformations.

:n burning of fuel inside the car

1.

Chemical energy is converted into heat energy,

which produces mechanical energy that move the car.

The electric generator (Dynamo):

2.

A part ofmechanical energy is converted into electric energy.

The car lamp:

3.

A part ofelectric

energy is converted intolight

energy.

The radio cassette:4.

A part ofelectric

energy is converted intosound

energy.

ditioning:he heater of the air con

5.

A part ofelectri

c energy is converted intoheat

energy.

Law of energy conservation:Energy is neither created nor destroyed but it is converted from oneform into another.

Energy& environment

Technology has negative effect since man used it in:

1. Wars& killing.

2. Massive destruction.

Some technology applications have results which cause

environmental pollution such as:

Electromagnetic pollution, chemical pollution, air, water, soil &noise.


4/18

Lesson 3

Heat and its transferring:Activity:

1. Put some identical metals spheres

in hot water.

2. Put other some in cold water

3. Leave them until be sure that

the spheres have the same

temperature of water around them.

4. Mix the cold& hot spheres together.5. Record the temperature by thermometer.

The temperature of the mixture is between the first& the:Obs

second due to the transfer of heat from hot balls to cold balls.

Conc:

Heat is transferred from high temperature to a lower onetill the temperature of the mixed spheres becomes equal.

Movement of the particles& temperature:Activity:

1. Put some balls in a plastic cup

& record the temperature.

2. Invert another similar cup onthe first tightly.

3. Shake the 2 cups from 20 to30 times

then determine the temperature..he ballsbetween tfrictionThe temperature rises due to theObs:

Conc:

Temperature is raised asspeed

of spheres increases.

i.e. as the kinetic energy of the particles increases.


5/18

ture & frictionTempera

1. Rub your hands together.Obs: They feel hot.Activity:

1. Invert your bicycle.2. Let the pedal turn fast, then

press the bicycle breaks strongly.

3. Touch the frame of the wheel when it stops.Obs: It feels hot.Conc:

Friction turns mechanical energy into heat energy.

Heat energy

tois a form of energy which transfers from higher temperatureHeat energy:lower one.

tates the direction of heat energyis the condition which s:Temperature

weather from or to the object when it comes in contact with another.

N.B.

Temperature is proportional to the kinetic energy of the particles.

Heat transferring

1. By conduction:

1. Put a metal spoon in a cup of hot tea.

Obs: You feel the hotness of the spoon.Conc: Heat is transferred through solids by conduction.

convection:By2.

Heat transfers in gases& liquids by convection, where the hot molecules

rises upwards, while colder molecules have more density& fall down.radiation:3. By

Heat transfers in gases& space by radiation without any need of

material medium.


6/18

eat transferringApplications on h

Give reasons:

The freezer is found at the top of the fridge.1.

Because when the air is cooled, its density increases so it falls

down to cool the food in the refrigerator.

The electric heater is placed down on the ground.2.

Because when the air is heated, its density decreases so it rises

up to warm the room.

* Technological applications to produce heat:

HeaterWater heater

Stove

Ovens.

Some of these applications work by petrol fuel

(non- permanent resource).

Some of them work with solar energy as a permanent source.

Give reasons:The solar energy is preferred over other types.

Because it is considered as the cleanest source of energy

(doesn't pollute the environment)


7/18

Unit 3 (Lesson 1)

1. Diversity of animals

Animals differ in:* Shape

* Size

* Way of feeding

* The environment that they live in.Examples:

Big animals such as elephant& rhinoceros, small animals*

as rabbit, rats& lizard.* There are animals live in water such as fishes, crocodiles&

hippopotamiOthers live on land such as horse, lion& dog.

2 . Diversity of plants

* Huge trees such as camphor& palms.

* Short weeds such as clover& gargeer.

* Plants carry large-sized leaves such as banana plants.* Plants carry small-sized leaves such as molukhiyah.

3. Diversity of micro-organisms

Diversity between micro-organisms which

can't be seen by naked eye they can be seen

only under microscope.

* Unicellular micro-organisms such as,

Amoeba, Euglena& Paramecium.

They differ in shape& the way of movement.


8/18

Give reasons:

Scientist classifies the living organisms.

Due to the enormous diversity of living organisms, scientistsclassify them to ease their studying.

rding to their shapes (external appearance):Acco1.

Most plants can be distinguished

into roots, stems& leaves such as

Corn, Wheat, Palms& Camphor

Some plants cant be

distinguished into roots,

stems& leaves such as

Algae( green, red & brown)

According to the2.reproduction

Formation of seeds

Angiospermsymnosperms

( Flowering plant)The seeds are formed * Monocotyledon

inside cones such as Maize& WheatPine plant& Cycas

* Dicotyledons

Beans& Peas

Formation of

spores

Voughair&Adiantum areknown as Ferns


9/18


10/18

g to the type number of teeth.lassifying mammals accordin

th5

Mammals are classified according to the existence of teeth into:

Edentates ( Teeth less)

1)

Such as sloth& Armadillo

) Mammals having teeth:

2

According to the shape& type, they are divided into:Sharp incisors

Are divided according to their

number in each jaw into:

Lagomorphs

They have two pairsof incisors in the

upper jaw& only

one pair in the

lower jaw.

Such as therabbit.

tsoden

They have onepair of incisors

in each jaw.

Such as:Rat Squirrel.

Pointed

anines

solar

with sharp

projections.

Such as:Lion

&

tiger

Front teeth

Extending

outwards.

Such as:Hedgehog

(Why?)To capture

the insects.


11/18

TaxonomyIt is a branch of biology searching the similarities& the differences among

living organisms, and placing the similar ones in groups according to a certain

system in order to ease their studying.

Species

It is the basic classification unit for living organisms.* Linnaeus had considered the species as fundamentals of a natural

classifying system.

Species:

Is a group of more similar living organism's shape that can reproduce to

give birth of new fertile individuals that are able to reproduce therefore

keeping the existence of the species.

Activity: Classifying a group of animals into species.

The best classification is putting them into 3 groups;

the cat group, the dog group& the rabbit group.

* Cats differ from each other, but they are more different than

rabbits.

* It is impossible for cats to mate to rabbits whereas mating can take

place between two any couples of cats whatever the difference is in

shape or size.N.B

fertileproducecan'tare mating, theyzebradonkey& aWhen a*

.Zonkeyknown asindividuals

B. they are different species


12/18

2Lesson

* Multiplicity of environments where living organisms live is the mostimportant reasons for diversity in order to cope with the environmental

changes such as climate change, food& existence of water.

A camel pad a horse hoof.:Activity 1Give reasons:

1. The camel pad ends in a thick flat one.To enable the camel walking through the hot desert sands without

sinking.

2. The horse hoof ends in a strong solid end.To help the horse go through the rocky soil.

SoBoth of them cope with the method of motion& the environment condition

Adaptation.known asach of them lives this iswhere e

Adaptation:

Is a modification in a living organism or its body structure or even thebiological function of its organs to become more adapted to the

environmental conditions where it lives in.

Types of adaptation

BehavioralFunctionalStructural

(anatomical)As in bird migration

or activity of birds

or animals indifferent times as

day& night.

The ability of some

organs& tissues to do a

specific function assecreting sweat in hightemperature as in human

or secreting poison as insnake.

It studies the

structure of

one body organsuch asHorse hoof&Camel pad.

tion:he reasons of adapta

1. To get food is the most important reason.2. To escape from its enemies in dangerous situations.


13/18

Modifications in mammal's limbs enable them to move in different ways

that match with their environment& life style.

***Modification of front limbs in mammals:

1. Paddles of whales& dolphins for swimming.

.2. Wings of bats for flying

3. Legs of horse for running.

4. Long arm of monkeys for climbing& catching things.


14/18

Bird's beak& legs are modified& varies in their structure to adapt

the food type& environmental conditions they have.

The shape of beak legshe bird

* Beak: Sharp& strong crooked beaksTo enable to tear the prey.

*Legs

: Four fingers ending with strong sharp

claws ( 3 front fingers& a back one)

To be able to bend to control pouncing

the prey.

Predatory1.Hawks& Vultures

*Beak

: Long& thin to help them to pick up

worms& snails.

* Legs: Long& thin ending with thin fingersto walk in the existence of water.

that feed onirds2.shallow water worms&

Snails such as hoopoe.

*Beak

: wide indented in the two sides to help

them filter the food from water.* Legs: Palm legs to help swimming.

uch asater birds s

3.ducks& geese which

feeds on mosses & fish


15/18

:eating) plants-Adaptation in insectivorous ( insect

Examples: Drosera, Dieonea Halophila

* They are self feeding green plants that

can perform photosynthesis process& make carbohydrates.

* They can't absorb the nitrogenous substances needed to make proteins.

So some parts of these plants are modified in order to pounce&

digest insects then absorb the nitrogenous substances that their

bodies need.


16/18

3esson

Give reasons: The dinosaurs mammoth perished extinct.

* Because they couldn't adapt to the environmental changes.

Examples of adaptation in living organisms:

2. Aestivation1. HibernationTo overcome the rising in

Temperature& shortage of

water:some animals becomen summer,

in a dormant& hide in humid

burrows.

Such asjerboa, desert snail&some insects.

To overcome the decreasing of

temperature:

some animals hide inn winter

reptiles& someburrows as

insects

or bury themselves in mud, stopfeeding& their activities are

as frogs.decreased

, when the conditionsIn spring

become favour, they return back

to their normal activities.

. Bird migration:

3

* Some species of birds are adapted to the environmental conditions bymigration from cold& polar regions during winter to more lighted& warmer

regions for reproduction.

* Then they return back to their original habitats in spring.

* These birds inherit this behavior where they migrate into the same placesQuail bird.at the same times every year. Example:


17/18

4. Adaptation for hiding:Some animals can color themselves with the dominant colours in the

environment.which is hardly discovered by its enemies because it looks

nsecteaf

1.

like the plant leaves in colour& shape of wings.which looks like the branches of plants as well.nsecttick2.

environment to becolors itself with the dominant colours of thehameleon3.

hidden from its preys of insects to capture them& feed on.

Camouflage:

Is the ability of some living organisms to be hidden from their enemies or

to capture the preys in the predator species.


18/18

Camel is the desert shipGive reasons:

Camel is considered as one of the most adapted animals to live in desert.

* Some adaptation features in camel:

1. The Camel has a plenty number oflacrimal glands&

2 rows of long eye lashes.* To protect its eyes from sandstorm.

2. The camel can control the opening& closing of its nostrils.

* To protect its nose from sandstorm.3. Camel's ear is small& covered with dense hair from inside.

* To protect it from sand& dust.4. The camel's fur thickness differ at its body reagions.

* To protect it from the extreme cold at night& to ease heat

loss by radiation during daylight.5. The camel's legs end in a broad pad.

* To prevent it from sinking in smooth sand.6. The camel has a thick skin.

* To protect it from high temperature of the soil.7. The forked upper lip camel's mouth& the strong enamel of its teeth.

* To enable it to eat the spiny& dry desert plants without

harming it.8. The camel stores an amount of fats in its hump.

* To keep its survival for 3- 4 months without eating any food.

9. The camel's blood temperature is not constant as in other mammals,It changes from 340C during the morning to 410C duringdaylight hours.

* To not lose too much water through sweating.

unit 2 laws of conservation

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