Summary

Unit 1 – Work and Energy ...................................................................... 2

Sessions ........................................................................................................................ 6

Unit 2 – Radioactivity and its applications ........................................... 9

Sessions ...................................................................................................................... 14

Unit 3 –Universe and Solar System ......................................................18

Sessions ...................................................................................................................... 22

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Unit 1 – Work and Energy

I) Work

Definition: The work W done by a constant force acting on an object and causing a

displacement parallel to , is equal to the product of the magnitudes of and .

Expression: W=F.d where

Conditions to have a work

1. Point of application of the force must move with the displacement

2. Displacement take place

Remarks:

1. The work done by forces perpendicular to the motion is equal to zero.

2. When many forces act on an object, the total work done by these forces is equal to the

sum of the work done by each force individually

II) Forms of energy

Definition of energy: Energy is the ability to do work and its SI unit is joules

Forms:

1. Kinetic energy: energy due to motion

Expression K.E= mv2 where

Notes:

a) Any object at rest has a zero K.E

b) Any object is released without initial velocity

K.E=0J

c) To convert from Km/h to m/s divide by 3.6

2. Gravitational potential energy: energy due to position

Expression G.P.E=mgh where

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When determining the G.P.E a reference must be taken where

G.P.E (above reference) >0J

G.P.E (below reference) <0J

G.P.E (reference) = 0J

3. Mechanical energy: M.E= K.E + G.P.E

a) Conservation of M.E: if the resistive forces (friction and air resistance) are considered to be

neglected then the mechanical energy is said to be conserved.

Law of conservation of mechanical energy: ∆M.E=M.Ef-M.Ei=0J M.Ef=M.Ei

b) Non conservation of M.E: is the presence of the resistive forces that play a role in the loss of

some M.E and converting them into heat

Law of non-conservation of M.E: ∆M.E=M.Ef-M.Ei=Q=Wf= -fd where

Q: is the quantity of heat in [J] and Wf is the work done by the friction force

f: is the magnitude of the friction force [N] and d is the displacement in [m].

4. Heat or Thermal energy: energy transferred between two bodies when they have different

temperature.

5. Chemical energy: electrostatic potential energy (interaction between electrons and nucleus).

Example: Batteries, fuels.

6. Electrical energy: the electric energy consumed is a conductor is:

W=VQ=VIt=Pt where

Energy Conversions:

Resistor: chemical electrical thermal (heat)

Motor: chemical electrical mechanical.

7. Nuclear energy: binding energy between nucleons (protons and neutrons).

III) Mass energy equivalence

Einstein’s Expression: E=mc2 where

c=3x108m/s then c

2=9x10

16m

2/s

2

IV) Principle of conservation of energy 1. Energy can be created nor destroyed

2. We can convert from one form of energy to another

3. Any energy conversion is accompanied by heat.

V) Efficiency of energy conversion a) An energy converter is an apparatus that can transform energy form one form to another form.

b) The efficiency ρ of a converter is equal to the ration of the output energy (useful energy) to the

input energy (received energy).

ρ= then percentage of ρ= x 100

Remarks:

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1. 0< ρ<1 that is 0%< ρ<100%

2. For a conversion to be efficient ρ>0.5 or ρ>50%.

c) Law of conservation of energy: Ein=Eout+ Heat Energy

Example

Solar panels: Are energy converters form radiant energy (primary) into electric energy

(secondary)

Efficiency ρ= =

Advantages:

1. No pollution

2. Sun light is free renewable source

Disadvantages:

1. Intensity of light is nit constant

2. Low efficiency

3. Solar panels are expensive.

VI) Sources of energy

Some energy conversions

a) Plants and trees: From radiant energy to chemical energy. b) Wind mills: From wind energy to electric energy.

VII) Pollution

Definition: Pollution is the contamination of the earth’s environment with materials that interfere

with human health, the quantity of life, or the normal functioning of the living organisms.

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Effects of some gases:

- Sulfur dioxide: Bronchitis and green house effect ( Warming the Earth’s surface)

- Carbon monoxide: heart disease

- Lead and mercury: cancer

- Smokes: cancer

- Chloro – Flouro – Carbon (CFC): global warming

- Methane: global warming

- DDT: poisons birds

- Carbon dioxide: reduce the escape of heat from the earth without blocking radiation

coming from sun which lead to global warming

Remark: T (K) = T ( o

C ) +273

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Sessions Question 1 االستثنائية 2016 العام دورة

Question 2 العاديه 2016 العام دورة

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Question 3 2013 للعام العادية الدورة

Question 4 : العادية 2011 العام دورة

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Question 5 االستثنائية 2012 العام دورة

Question 6 : االستثنائية 2011 العام دورة

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Unit 2 – Radioactivity and its applications

Nuclides and Isotopes

Any atom or nucleus is denoted by

Where

Atom consists of protons, electrons, neutrons.

Where Z=Np=Ne and Nn=A-Z (In a neutral atom).

Isotopes: Nuclei having the same atomic number Z and different mass number A

Examples: 1. carbon atoms

2. Hydrogen deuterium Tritium

Radioactivity

Definition: Radioactivity is the spontaneous transformation of a nucleus into another with the

emission of radioactive radiation.

Radioactive decay or emission

1. Alpha decay (α decay)

Alpha decay is the spontaneous transformation of a nucleus X (A>80) to a nucleus Y with the

emission of an alpha particle.

Equation +

Laws of conservation (Soddy’s Laws)

a) Law of conservation of mass number A: A=A’+4

b) Law of conservation of charge number Z: Z=Z’+2

Properties of α particle:

i) Low penetrating power

ii) V=20000Km/s

iii) Positively charged particles

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2. Beta minus decay (β- decay)

Beta minus decay is the spontaneous transformation of a nucleus X (rich in neutrons) to a

nucleus Y with the emission of Beta minus particle (electron).

Equation +

Laws of conservation (Soddy’s Laws)

a) Law of conservation of mass number A: A=A’

b) Law of conservation of charge number Z: Z=Z’-1

Properties of β- particle:

i) V=270000Km/s

ii) Good penetrating power

iii) Negatively charged particles

3. Beta plus decay (β- decay)

Beta plus decay is the spontaneous transformation of a nucleus X (rich in protons) to a nucleus Y

with the emission of Beta plus particle (positron).

Equation +

Laws of conservation (Soddy’s Laws)

a) Law of conservation of mass number A: A=A’

b) Law of conservation of charge number Z: Z=Z’+1

Properties of β+

particle: positron is the antiparticle of electron it has the same physical

properties of electrons but opposite charge.

i) V=270000Km/s

ii) Good penetrating power

iii) Positively charged particles

iv) Same mass of electron.

4. The Gamma radiation (γ rays)

Definition: It is an electromagnetic radiation (photons) emitted as the nucleus formed after

disintegration drops to a lower energy state

De – excitation equation: * +

*: X is in an excited state.

: X is a lower energy level

(ground state). Properties of γ ray

i) High penetrating power

ii) Massless

iii) Has the speed of light C

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Half life and Activity of a Radioactive Sample

Half life: Time needed by a radioactive sample to decay into half its initial value.

Half life is denoted by T and its SI unit is [sec]

Activity: number of disintegration per unit of time (sec).

Activity is denoted by A and its SI unit is Bequerel [Bq].

Consider at t0=0sec a radioactive sample of mass m0

At t=T m= where m is the disintegrated (decayed) mass

At t=2T

At t=nT m= where m is the disintegrated (decayed) mass

The remained mass id mr=m0-m

Note: A and N (number of atoms in the sample) satisfy this equation that is if at t0=0sec the initial

activity was A0 and the initial number of atoms is N0 then at t=nT A= and N=

Mass defect and liberated energy For any nuclear reaction

Mass defect (loss of mass) Δm = mbefore - mafter > 0Kg Mass can be expressed in u where 1u=1.66x10

-27Kg

This loss of mass appears as liberated energy ΔE = Δm.C2

Energy can be expressed in MeV where 1J=1.6x10-13

MeV and 1MeV=106eV

If the mass of a sample of radioactive nuclei is m then the number of nuclei in this sample is

equal to: N= where m(sample) and m(one mole) are in kg.

If m (sample) is in g and m (one mole in u) then N= NA where NA is the

avogadro’s number NA=6.03x1023

Stimulated Nuclear Reactions

Fission

Definition: Fission is a stimulated nuclear

reaction during which a heavy nucleus (A>80) is divided into two lighter nuclei under the

impact of a neutron.

Properties of the bombarded neutron ( ):

1. Neutral

2. Can penetrate the atom reaching the nucleus

3. Low speed that is kinetic energy K.E=0.2eV

Equation: + + + x

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Laws of conservation (Soddy’s Laws)

a) Law of conservation of mass number A: A+1=A’+A’’+x

b) Law of conservation of charge number Z: Z=Z’+Z’’

Note: Fission reaction emits x number of neutrons of high kinetic energy that can make chain

reaction.

Fusion

Definition: is a stimulated nuclear reaction that consist in the binding of two light nuclei to form

one heavier nucleus

Conditions of the reaction:

Fused nuclei are positively charged so they must have high K.E around 0.1MeV to overcome the

repulsion between them.

The Absorbed Dose and Physiological Equivalence of a Dose

Absorbed Dose: Energy Transferred per unit of mass [kg]

SI unit [Gy] where Gy=1J/kg

Dose= where mass (of the organ) is in Kg and Energy (received by the rogan) in J

Effects:

Weak Dose Strong Dose

1. Burns 1. Destroying of cells and tissues

2. Wounds 2. Death

3. Genetic mutations

4. Cancer

Physiological Equivalent of a Dose = Absorbed Dose x Relative Biologic Efficiency

P.E = Dose x R.B.E SI unit [Sv]

Biologic and Genetic Effects of Absorbed Dose

1. DNA damaging

2. Genetic mutations

3. Malformation

4. Long – term cancer

Nuclear Wastes: Products of fission reactions

Physiological equivalent of

dose in Sv Effects

> 10 100 % mortality

5 50 % mortality ; cancer, blood troubles , …

2 10 % mortality ; cancers, diarrhea, vomiting, …

1 Digestive troubles, sterility, increasing risk of cancer…

0.05 Modification of the blood formula

< 0.05 No observable effect

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Protection against Radioactive Radiations:

*People should be evacuated away from them

*Use leaded wall (hardly penetrated)

*Specific Medicines that ionize them

*Using Filtering masks

*Protective Clothing

.

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Sessions Question 1 االستثنائية 2016 العام دورة

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Solution 1 االستثنائية 2016 العام دورة

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Question 2 لعاديها 2016 العام دورة

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Question 2 العاديه 2016 العام دورة

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Question 3 2013 للعام العادية الدورة

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Question 4 : العادية 2011 العام دورة

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Question 5 االستثنائية 2011 العام دورة

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Question 6 : االستثنائية 2012 العام دورة

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Unit 3 –Universe and Solar System

Some Definitions: *Fixed Stars: Distance between them is fixed even they are in motion.

*Celestial bodies: Natural objects visible in the sky - planets, stars, meteoroids, etc

*Astrology: An art that study stars in order to determine their influence on terrestrial events on lives

and character of people, and their destiny.

*Astronomy: Science that study these characteristics of celestial bodies

Position

Structure

Evolution

*Cosmology:

field of astronomy that studies these characteristics of universe

Structure

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Origin

Evolution

*Astrophysics: Science that studies the constitution, the physical properties, and the evolution of stars

Geocentric Theories

Plato and Aristotle Theory Postulates:

*The Universe is spherical.

*All celestial bodies including earth are spherical.

*Earth is immobile (at rest) and is at the center of the universe.

*Any celestial motion must be uniform circular motion ( constant velocity) around the earth

*The celestial bodies complete their revolution around the earth at different distances. The fixed star

are the farthest from earth and are carried by a sphere whose period of revolution is one day (time to

complete one cycle is T=1day)

Ptolemaic System

Postulates:

*Earth is immobile and is at the center of the Universe.

*The Moon and the Sun Move uniformly along two circular orbits having the Earth as a center.

*The other planets move uniformly along small circles called epicycle moves along circular orbit

around the Earth. This orbit is called the deferent

*The planets are located around the Earth in the following order from closet to farthest: The Moon,

Mercury, Venus, the Sun, Mars, Jupiter and Saturn.

Galileo: made the first telescope and support Copernicus Theory

Tyco Brahe: was a remarkable observer and never accepted Copernicus theory

Heliocentric Theories

Copernicus Theory Postulates:

1. The Sum is immobile and is at the center of the spherical Universe.

2. Earth is a planet like any other.

3. The planets are carried by solid and transparent spheres, and each planet is driven by the uniform

rotational motion of its sphere around the sun. The fixed stars are carried by the sphere of longest

radius.

4. The period of revolution of planets depends on the radius (distance from sun)

5. Period of earth is one year also it rotate about itself in 24 hour

6. The Moon is a satellite of Earth and rotates in UCM around it

7. The planets are located around the Sun in the following order from closet to farthest: Mercury,

Venus, Earth, Mars, Jupiter and Saturn.

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Kepler’s Laws 1

rst law: The planets move along ellipses around the sun that is at one of the foci.

2nd

law: The velocity of a planet decreases as the distance increase and vice versa.

3rd

law: The period increase as the distance from sun increase.

Isaac Newton’s Law Any two bodies attract each other with a force that varies with the inverse of the square of distance

between them and with the product of their masses

Constituent of the Solar System:

The solar system lie in a plane called the ecliptic plane

a) The Sun: Center of this system

Sun Rotates about it self

Constitution

Layers of Sun

1. Inner layers:

Atmosphere layers:

Distance from the Sun to the Earth is 1AU where AU stands for astronomical unit.

b) Planets and their Satellites (Moons)

Some Remarks on planets:

1. Planet arrangement is according to their distance from sun ( closest to farthest)

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2. As the planet become farther from sun its temperature decreases.

3. Earth is the densest planet

i) Inner Planets 4. The closet planet to the Sun is Mercury.

5. There is an exception to remark 2 since Venus is farther than Mercury and Mercury are colder. This is

due to existence of CO2 on Venus that causes greenhouse effect.

6. Mercury and Venus have no moons.

7. Earth and Venus have a thick Atmosphere but only earth is favorable for living and this is due to

presence of O2 gas and water on Earth.

Atmosphere of Earth

8. Earth has one satellite and it is the Moon.

9. Mars is called the red planets due to presence of Iron Oxide also it has two moons called Phobos and

Demos.

ii) Outer Planets

10. Jupiter is the massive planet

11. Saturn is the lightest planet

12. Outer Planets (except Pluto) are called Jovian since they are giants, and they also have rings (largest

rings for Saturn formed of rocks and pieces of ice and Uranus have eleven rings formed of rocks).

13. Number of moons for

Jupiter 16

Saturn 18

Uranus 11

Neptune 8

Pluto 1 “Charon”

Moons (satellites): are solid objects that rotate around the planets.

c) Other Objects in the Solar System

1. Asteroids: Rocky Objects of

irregular shapes orbit (rotate)

around the Sun between Mars

and Jupiter.

2. Comets: Rotate elliptically

around the sun

Parts of a Comet (as shown in

the figure):

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3. Meteoroids: They rotate around the Sun; they formed of rocks and dust. They are heated and burned

due to the collision with the atmosphere; it causes a meteor when colliding with Earth.

Sessions Question 1 ائيةاالستثن 2016 العام دورة

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Question 2 العاديه 2016 العام دورة

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Question 3 2013 للعام العادية الدورة

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Question 4 : العادية 2011 العام دورة

Question 5 االستثنائية 2011 العام دورة

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Question 6 : االستثنائية 2012 العام دورة

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