1. Chapter 4- Electricity
Circuit= is the electric path through the
bulb, meter, battery and connecting wires.
4.1 Electricity
Electricity= is the flow of negative charges 4.3 Current, Voltage and Resistance
or electrons in a complete circuit.
Ohm’s Law:
Electrical current= is the rate of flow of
charges through conductor.
“ The current that flows through a conductor is
= it is measured using an
ammeter. directly proportional to the voltage across the
Ampere (A)= unit for measuring current end of the conductor, provided that the
Voltage= is the potential difference across temperature and other physical conditions are
the two points or the electrical energy unchanged.”
supply needed to move each unit of charge
from one point to another.
Voltmeter= unit in measuring voltage
Resistance= is a property of a material
VI= R or V=IR
that resists the flow of electric current
4.4 Parallel and Series Circuits
through. (Copper= good conductor for it
has a very low resistant. ..See the circuit diagram on page 123 Focus 3
Ohm ()= unit for measuring resistance
 Circuit symbols= are used to represent
Sources of electrical energy: generators, batteries
various components of a circuit.
and electrical cells, Dynamo, solar cells etc…
 Series circuit= is when two bulbs are
connected to each other in a circuit.
4.2 Measuring Electricity
 Parallel circuit= is when two bulbs are
Andre-Marie Ampere= is the one who connected separately to the same terminals
discovered the unit for electric current. of a battery.
Alessandro Volta= the one who
discovered the unit for voltage.
Georg Simon Ohm= is a German scientist
who discovered the unit measurement for
resistance.
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2. P=VI
4.7 Electronic Circuit P=E/t
Electronic circuit= are circuits with
microchips and other devices.
4.9 Importance of Safety Precautions in
Examples: the Use of Electricity
television set, computers, radios, phones, amplifiers
Fuse= is a safety device with low
Resistor= controls the level of current and resistance resistor that acts as a sacrificial to
voltages in order for other component to provide over current protection, of either the
work properly.
load or source circuit.
Diode= allows the current to flow through
it in one direction only. Double insulation= is a safety feature in
Transistor= is used to magnify or amplify an electrical appliance that can substitute for
signs. an earth wire. It makes electrical equipment
Integrated circuits (IC) or microchips relatively safe to use.
= contains many complete circuits such
diodes and other components. All
connections are formed into tiny chip of
silicon only a few millimeters square.
4.8 Cost of Electrical Energy
* Electricity is sold in energy unit kilowatt-hour
(kWh)
Electricity meter= is used in measuring
the number of kilowatt-hour you use at
home.
Power= the rate which an appliance uses
energy.
Watts= is used in measuring power
Power, P= Electrical energy , E
Time, t
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3. Chapter 5- Energy Changes Chapter 6- Forces and Motion
5.1 Forms of Energy 6.1 Acceleration
Energy= is the ability to do work. Acceleration= is the rate of change of
Joule (J) = unit of energy velocity.
Working energy= is the form of energy
that involves work being done. Formula: a= v-u
t
Stored energy= is the form energy stored
Acceleration= Change in velocity
by objects due to its position or its condition Time taken
Chemical energy= is the energy stored in
substances such as food and fuels. Weight= is the force gravity acting on the
Sound energy= is produced by vibrating object.
objects. Gravitational acceleration= is the
Heat energy= is found in hot objects. acceleration that an object experience due to
the force of gravity.
Light energy= is the energy radiated by
luminous objects. It enables us to see. Weight formula= w=mg
Electrical energy= consists of electrical
charges, which travel through electrical w= weight in (N)
conductors. m= is the mass in kg
Nuclear energy= is the energy stored in g= gravitational acceleration
the nucleus of an atom.
Law of conservation Energy: 6.3 Buoyant Force
“Energy can change from one form into
another but it cannot be destroyed or Buoyant force= is an upward force that acts as an
created.” object that is being completely or partially immersed in
a fluid.
Buoyant force= Actual weight- Apparent weight
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4. Chapter 7- Solar System, Stars and
Galaxies
Chapter 6- Forces andof the sun,
Solar system= is made up Motion
6.4 Static Friction and Kinetic Friction planets, moons, and others such asteroids,
meteoroids and comets.
Static Friction= is friction that acts on two
Sun= is the center of the solar system and
surfaces in contact that are not moving when a other planets. It provides heat and light to
force to move them is applied. the different planets.
Kinetic Friction= is a friction that acts on two
surfaces in contact that are moving 7.1 Planets
6.5 Static Friction and Kinetic Friction Planets= are big objects that go around the
sun.
Moment of force= is a measure of the ability
The Solar System
of a forces to turn or rotate an object on which
it acts.
Moment of force= Force x Perpendicular distance
from turning point
Lever= is a rigid object that is used with an
appropriate fulcrum or pivot to multiply the
mechanical force that can be applied to another
object.
6.4 Motion of Objects
Linear motion= is motion in a straight line
Projectile motion= is a motion when an
object is thrown or projected into the air.
Circular motion= is a motion when an object
moves in a circle.
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5. Earth
Earth is the third planet
Mercury Mercury is the innermost from the Sun, and the
planet in the Solar System. densest and fifth-largest of
It is also the smallest, and the eight planets in the
its orbit is the most Solar System. It is also the
eccentric of the eight largest of the Solar
planets. It orbits the Sun System's four terrestrial
once in about 88 Earth planets. It’s the only planet
days, completing three with living organisms.
rotations about its axis for
every two orbits. Circumference: 40,075 km
Distance from Sun: 149,600,000 km
Density: 5.52 g/cm³
Distance from Sun: 57,910,000 km Orbital period: 365 days
Length of day: 58d 15h 30m Mass: 5.972E24 kg
Orbital period: 88 days Population: 6,840,507,003 (2010)
Mass: 328.5E21 kg (0.055 Earth mass)
Gravity: 3.7 m/s²
Orbits: Sun Mars Mars is the fourth planet
from the Sun and the
second smallest planet in
Venus the Solar System. Named
Venus is the second planet after the Roman god of
from the Sun, orbiting it war, it is often described
every 224.7 Earth days. as the "Red Planet", as
The planet is named after the iron oxide prevalent
the Roman goddess of on its surface gives it a
love and beauty. reddish appearance.
Orbital period: 687 days
Length of day: 117d 0h 0m Distance from Sun: 227,900,000 km
Distance from Sun: 108,200,000 km Gravity: 3.711 m/s²
Gravity: 8.87 m/s² Length of day: 1d 5h 5m
Orbital period: 225 days Mass: 639E21 kg (0.107 Earth mass)
Mass: 4.867E24 kg (0.815 Earth mass) Density: 3.93 g/cm³
Orbits: Sun
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6. Uranus is the seventh
Uranus planet from the Sun. It has
the third-largest planetary
Jupiter Jupiter is the fifth radius and fourth-largest
planet from the Sun planetary mass in the Solar
and the largest planet System. It is named after
in the Solar System. It the ancient Greek deity of
is a gas giant with the sky Uranus, the father
mass one-thousandth of Cronus and grandfather
that of the Sun but is of Zeus.
two and a half times
the mass of all the
other planets in our Distance from Sun: 2,877,000,000 km
Gravity: 24.79 m/s² Solar System Discovered: March 13, 1781
Orbital period: 12 years combined. Gravity: 8.69 m/s²
Distance from Sun: 778,500,000 km Orbital period: 84 years
Length of day: 0d 9h 56m Mass: 86.81E24 kg (14.54 Earth mass)
Orbits: Sun Orbits: Sun
Moons: Europa, Io, Ganymede, Callisto,Amalthea, A
drastea, Thebe, Metis, Elara, More
Neptune
Neptune is the eighth
Saturn and farthest planet from
the Sun in the Solar
System. It is the fourth-
Saturn is the sixth
largest planet by
planet from the Sun
diameter and the third-
and the second largest
largest by mass.
planet in the Solar
System, after Jupiter.
Named after the Roman
god Saturn, its Distance from Sun: 4,503,000,000 km
astronomical symbol Orbital period: 165 years
Distance from Sun: 1,433,000,000 km god's
represents the Gravity: 11.15 m/s²
Gravity: 10.44 m/s² sickle. Length of day: 0d 16h 6m
Length of day: 0d 10h 39m Mass: 102.4E24 kg (17.15 Earth mass)
Orbital period: 29 years Orbits: Sun
Mass: 568.3E24 kg (95.16 Earth mass)
Orbits: Sun
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7. Sun= is at the center of the solar system. It
contains 99.85% of all matter in the solar
7.2 Asteroids, Comets and Meteoroids
system.
Asteroid= are small rocks similar to the
Characteristics of the Sun
materials that formed the planets.
Distance from the earth 149 680 000 km
Comets= is composed of dust and rock
Temperature of the Sun The surface temperature
particles mixed in with frozen water, is approximately 5500
methane and ammonia. degree Celsius. The
Halley’s comet= most popular comet atmosphere of the sun is
which takes 76 years to orbit the sun extremely hot which is
Meteoroids= are small rocky fragment of up to 1.5 to 2 million
debris floating through the space. degrees.
Composition of the Sun Composed of about 76%
Meteor= a meteoroid that burns up in
hydrogen and 22%
earth’s atmosphere. They are also called helium. Iron, nickel,
shooting stars silicon and carbon make
Meteorites= meteors name once they hit up the remaining 2% by
the earth. mass
Radius (size) 109 times that of the
7.3 Sun Earth
Density .27 times that of the
Sun Earth
Mass 330 420 times that of
The Sun is the star at the Earth
the center of the Solar
System. It is almost
perfectly spherical and
consists of hot plasma
interwoven with
magnetic fields.
Surface temperature: 5,778 K
Rotation speed: 1.997 km/s
Distance to Earth: 149,600,000 km
Declination: 63° 52.200'
Absolute magnitude: 4.83
Orbits: Galactic Center
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8. Solar flares= are huge explosions of
hydrogen gas on the surface of the sun.
Four-part Structure of the Sun
Prominences= are the masses of glowing
gas above the Sun’s bright surface.
Sunspots/solar spots= are dark patches
on the Sun where the temperature are lower
than the other areas of the sun.
Solar wind= is a flow of gases from the
Sun that disturbs and shakes the Earth’s
magnetic field.
Nuclear fusion= is the process by which
two or more atomic nuclei join together,
or "fuse", to form a single heavier
nucleus.
7.4 Stars and Galaxies
Star= is a hot ball of gases, mainly
Core= the center of the sun where nuclear hydrogen that gives out heat and light. They
reactions occur. The temperature here is vary in sizes, brightness and colors.
about 15 000 000 degree Celsius. Serius and Rigel= examples of bright
Photosphere= is the visible surface of the stars.
sun and where the sun’s energy is seen as
moving like boiling water. It’s one of the Type of Stars according to sizes
coolest layers of the Sun with temperature
of 600 degree Celsius. Type Size (relative to the
Chromosphere= a red glowing region of a diameter of the Sun)
gas. It’s part of the solar atmosphere with
Supergiant 100 to 1000 times bigger
the temperature of 15 000 degree Celsius.
Giant 10 to 100 times bigger
It’s visible to an eye during total solar
eclipse. White dwarf 1000 times smaller
Corona= outermost, tenuous atmosphere
of the sun. It’s extremely hot and with the
temperature of 2 000 000 degree Celsius. It
can only be seen during total solar eclipse.
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9. Galaxy= is a system of stars.
Milky Way= is fairly large spiral galaxy
Classification of Stars
which consists of 200 billion stars with
Color Temperature(C) Example the sun as being one of them.
Blue 25 000 Spica
Bluish-white 11 000- 25 000 Rigel 12 famous Constellations/ zodiac signs are:
White 7500- 11 000 Vega Aries
Yellowish- 6000-7500 Capella Taurus
white Gemini
Yellow 5000-6000 Sun Cancer
Orange 3500-5000 Arcturus Leo
Red  3500 Antares Virgo
Libra
Constellation= is a group of stars with a Scorpio
pattern of maybe an animal or a familiar Sagittarius
object. Capricorns
Nebulae= are clouds of gas or dust. It’s Aquarius
where fresh stars is being formed. Pisces
Red giant= is a luminous giant star of low
Types of Galaxies
or intermediate mass (roughly 0.5–10 solar
masses) in a late phase of stellar evolution. Elliptical
White dwarf= also called a degenerate
Spiral
dwarf, is a stellar remnant composed mostly
of electron-degenerate matter. Irregular
Supernova (abbreviated SN, plural SNe
after supernovae) is a stellar explosion that
is more energetic than a nova.
Neutron star= is a type of stellar remnant
that can result from the gravitational
collapse of a massive star during a
supernova event.
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10. Chapter 8- Space Exploration
Astronomy= is the study of objects in the
outer space.
Chinese, Arabs and Greeks= made
detailed observation of the stars and
planets.
Aristotle= suggested that the Earth was
the center of Universe.
Nicolaus Copernicus= claimed that the
sun is the center of the Solar system.
Hans Lippershey= invented the first
telescope.
Hubble Space Telescope= the most
famous space telescope.
Sputnik 1= was an artificial satellite
launched by Russians in 1957
Yuri Gagarin= was the first man to orbit
the Earth in 1957
Neil Armstrong= was the first man to
walk on the Moon.
Skylab= was the first space station sent to
the space by Americans in 1973
International Space Station= was
launched in 1998 to provide a platform for
the scientists to perform researches.
Satellite purposes:
 Telecommunication
 Weather forecasting
 Military purposes
 Remote sensing
 Disaster management
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