Transcript Document

Preparatory Program in Basic
Science(PPBS001)
PART I
PYSICS
Instructor:
Prof.Dr.Hassan A.Mohammed
Syllabus:
The course will cover the following topics
UNIT (0) INTRODUCING SCIENCE; MATH BACKGROUND
0.1 Science
0.1.1 Useful Definitions
0.1.3 Science Categories 0-5
0.1.2 The Scientific Method
0.2 Using Units in Science
0.2.1 Rules for Using Units
0.2.1.1 Citing physical quantities with unit
0.2.1.2 Including units in intermediate steps
0.2.1.3 Preserving dimensional consistency
0.2.1.4 Keeping the correct case for units and prefixes
0.2.2 The International System of Units (SI)
0.2.2.1 Two Major Systems of Units
0.2.2.2 Characteristics of the SI
0.2.2.3 Conversion between the SI and USCS Systems
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0.3 Trigonometry Overview
0.3.1 Basic Ratios
0.3.2 The Unit Circle
0.3.3 Sine Function
0.4 Scalars and Vectors
0.4.1 Definitions 0.4.2 Decomposing and Adding Vectors
0.4.3 Scalar Product of Vectors
0.4.4 Vector Product of
Vectors
Unit (1 ) : MOTION :
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1.1 Motion
1.1.1 Displacement & Distance
1.1.2 Velocity & Speed
1.1.3 Acceleration
1.2 Motion in One and Two Dimensions
1.2.1 Linear (or 1-D) Motion
1.2.1.1 Description
1.2.1.2 Acceleration of Gravity
1.2.1.3 Examples
1.2.2 Planer (or 2-D) Motion
1.2.2.1 Description
1.2.2.2 Relative Motion
1.2.2.3 Examples
2 - NEWTON’S LAWS :
2.1 Newton’s First Law of Motion
2.1.1 Definitions
2.1.1.1 Inertia and Mass
2.1.1.2 Force
2.1.1.3 Weight
2.1.1.4 Mechanical Equilibrium
2.1.2 Statements of the 1st Law
2.1.3 Spring-Effect Forces
2.1.3.1 Introducing the Spring
2.1.3.2 Support Force
Tension
2.1.4 Demonstrations of the 1st Law
2.2 Newton’s Second Law of Motion
2.2.1 Statement of the 2nd Law
2.2.2 Opposing Forces
Friction
2.2.2.2 Inclined Plane
Air Resistance
Air Drag
2.3 Newton’s Third Law of Motion
2.3.1 Force, and the 3rd Law
Conceptual Physical Science vii M.M. al-Jibaly
2.3.1.1 Defining Force
2.3.1.2 Statement of the 3rd Law
2.3.1.3 Important notes
2.3.2 Examples of Newton’s Third Law
2.3.2.1 Simple examples
2.3.2.2 The Horse’s Dilemma
UNIT ( II )
3 - MOMENTUM & IMPULSE:
3.1 Momentum
3.2 Impulse
3.2.1 Definition
3.2.3 Important notes
3.2.2 Relationship to Momentum
3.2.4 Car-Crash Example
3.3 Conservation of Momentum
3.3.1 Derivation
3.3.2 Collisions
3.3.2.1 Definition
3.3.2.2 Types
3.3.2.3 Discussion
3.3.3 Simple Examples
3.3.3.1 Zero Initial Speeds
3.3.3.2 Zero Final Speeds
3.3.3.3 Worked Exercise
4- ENERGY, POWER, & SIMPLE MACHINES
4.1 Work, Energy, Power
4.1.1 Work
4.1.1.1 Definition
4.1.1.2 General Equation for Work
4.1.2 Energy
4.1.2.1 Definition
4.1.2.2 Different Forms of Energy
4.1.2.3 Observing and Using Energy
4.1.2.4 Conservation of Energy (and matter)
4.1.2.5 Common Energy Units
4.1.3 Power
4.1.3.1 Definition
4.1.3.2 Common Power Units
4.2 Mechanical Energy
4.2.1 Potential Energy
4.2.1.2 Forms of Potential Energy
4.2.1.4 Important Notes
4.2.2.1 Definition
4.2.2.3 Important Notes
4.2.3 Example of Mechanical Energy
4.2.3.1 Pile Driver
4.2.3.3 Bicycle up a Hill
4.2.1.1 Definition
4.2.1.3 Gravitational Potential Energy
4.2.2 Kinetic Energy
4.2.2.2 Derivation
4.2.3.2 Throwing a Ball
4.2.3.4 Pendulum.
4.3 Efficiency
Definition
4.4 Simple Machines
4.4.1 Definition
4.5 Worked Exercises
Example : Friction
4.4.2 Types
4.4.3 Law
UNIT ( III)
5- ELECTRICITY
5.1 Electrostatics
5.1.1 The Atom
5.1.1.1 Constituents
5.1.1.2 Atomic Charges
5.1.1.3 Large-Scale Charges
5.1.1.4 Conservation of Charge
5.1.2 Coulomb’s Law
5.1.2.1 Statement of the Law
5.1.2.2 Important Notes
5.1.3 Electric Field and Potential .
5.1.3.1 Electric Field
5.1.3.2 Electric Potential
5.1.3.3 Capacitors
5.1.4 Conductors and Insulators
5.1.4.1 Definitions
5.1.4.2 Charge Polarization
5.1.4.3 Lightning
5.1.5 Charging Methods
5.1.5.1 Charging by Friction
5.1.5.2 Charging by Contact
5.1.5.3 Charging by Induction
5.1.5.4 Charging by Conduction
5.2 Electrodynamics
5.2.1 Electric Current
5.2.1.2 Important Notes
5.2.2.1 Definition
5.2.3 Charge “Pumps”
5.2.4.1 Ohm’s Law
5.2.4.3 Parallel circuits
5.2.1.1 Definition
5.2.2 Electric Resistance
5.2.2.2 Resistivity
5.2.4 Electric Circuits
5.2.4.2 Series circuits
5.2.5 Electric Power
5.3 Alternating Voltage
5.3.1 Definition
5.3.2 Wave Behavior and Rectification
5.3.2.1 Wave Behavior
5.3.2.2 Rectification
5.3.3 Safety Considerations
UNIT (IV) ;
6- ATOMS, ELEMENTS, & THE PERIODIC TABLE
6.1 Introduction: the Submicroscopic World
6.2 Atoms
6.2.1 The Smallest Building Blocks
6.2.3 Charges within the Atom
6.2.4.1 Distances inside the Atom
6.2.2 The Atom’s Three Constituents
6.2.4 The Atom is Mostly Empty
6.2.4.2 A Puzzling Question
6.3 Atomic and Mass Numbers, and Atomic Mass
6.3.1 Atomic Number
6.3.1.1 Notes
6.3.2 Mass Number
6.3.3 Masses within the Atom
6.3.3.1 Note
6.4 Elements and Isotopes
6.4.1 Elements
6.4.2 Isotopes
6.4.2.1 Examples
6.4.2.2 Notes
6.5 The Periodic Table
6.5.1 Overview
6.5.2 Metals, Nonmetals, and Metalloids
6.5.2.1 Metals
6.5.2.2 Nonmetals
6.5.2.3 Hydrogen
6.5.2.4 Metalloids
6.5.3 Organization of the Periodic Table
6.5.3.1 Groups
6.5.3.2 Periods
6.5.3.3 Inner Transition Metals
7- PHYSICAL & CHEMICAL PROPERTIES; COMPOUNDS .
7.1 What Is Chemistry?
7.1.1 The Science of Matter
7.1.3 Basic vs. Applied Research
7.2 Physical & Chemical Properties
7.2.1 Phases of Matter
7.2.1.1 Defining the Three Phases
7.2.1.2 Change of Phase
7.2.2 Physical Properties
7.2.2.1 Description
7.2.2.2 Physical Change
7.2.2.3 Examples
7.2.3 Chemical Properties
7.2.3.1 Description
7.2.3.2 Chemical Change
7.2.3.3 Examples
7.2.4 Between Physical & Chemical Changes
7.3 Molecules and Compounds
7.3.1 Molecules
7.3.2 Compounds
7.3.3 Naming Compounds
7.3.3.1 Guideline 1
7.3.3.2 Guideline 2
7.3.3.3 Guideline 3
7.4 Mixtures
7.4.1 Definition
7.4.2 Examples
7.4.3 Types of Mixtures
7.4.4 Separating Mixtures
UNIT (V) :
8- BONDING .
Introduction
8.1 Chemical Bonding
8.1.1 Introduction
8.1.2 Arrangment of Electrons
8.1.2.1 Electron Shells
8.1.2.2 Valence Electrons
8.1.2.3 Electron-Dot Structures
8.1.3 Role of Valence Electrons in Bonding
8.1.3.1 Paired and Unpaired Electrons 8.1.3.2 The Octet Rule
8.1.3.3 Application of the Octet Rule
8.2 Ion Formation and Bonding
8.2.1 Forming Ions
8.2.1.1 Guidelines
8.2.1.2 Important Notes
8.3 Ionic Bonds
8.3.1 Definition
8.3.2 Important Notes
8.4 Metallic Bonds
8.4.1 Definition
8.5 Covalent Bonds
8.5.1 Definition
8.5.2 Important Notes
8.6 Polar Bonds and Polar Molecules
8.6.1 Definition
9- CHEMICAL REACTIONS:
Introduction
9.1 Chemical Equations
9.1.1 Reactants & Products
9.1.2 Mass Conservation & Balancing
9.1.3 Balancing Unbalanced Equations
9.2 Acid, Bases, and Their Reactions
9.2.1 Acids
9.2.1.1 Examples
9.2.2 Bases
9.2.2.1 Examples
9.2.3 Acid-Base Reactions
9.2.3.1 Definition
9.2.3.2 Examples
9.2.3.3 Reverse Reaction
9.2.3.4 Worked Example
9.2.4 Salts
9.2.4.1 Definition
9.2.4.2 Examples
9.2.4.3 Neutralization
9.2.4.4 Notes .
9.3 Molecular Ions
9.4 Solutions
9.4.1 Definitions
9.4.2 Types of Solutions
9.4.3 Saturation and Concentration
9.4.3.1 Saturation
9.4.3.2 Concentration9–161
9.4.3.4 Molarity
9.5 Acidic, Basic, and Neutral Solutions
9.5.1 Amphoteric Substances
9.5.2 Three Types of Aqueous Solutions
9.5.2.1 Neutral Solution
9.5.2.2 Acidic Solution
9.5.2.3 Basic Solution
9.5.2.4 Notes
9.6 The pH Scale
9.6.1 Logarithms
9.6.2 pH
9.7 Oxidation-Reduction Reactions
9.7.1 Definition
9.7.2 Oxidizing and Reducing Agents
9.7.3 Methods of Identifying Oxidation-Reduction
9.7.3.1 First Method
9.7.3.2 Second Method
9.7.3.3 Third Method
Lecture 1 & 2
UNIT (1) : 1- MOTION
1.1 Motion :
Motion is the study of an object’s change of location .
An object’s motion is determined by its
displacement (d), velocity (v), and acceleration (a).
Object: car – crate(box)- rock-ball –boat-child
1.1.1 Displacement & Distance :
Displacement is a vector quantity.
It represents the distance covered by an object and the
direction in which the object moved.
We usually use the symbol ( d ) for displacement.
The magnitude (d) of the displacement is a scalar quantity
called distance. The SI unit for distance is the meter (m).
1.1.2 Velocity & Speed:
Velocity is defined as the rate of change in displacement:
Velocity = displacement ÷ time interval, or :
v = d/∆t
Speed is the magnitude (v) of the velocity. It is a measure of how
fast an object moves, or the rate at which distance is covered.
Objects rarely move at a constant speed. Speed usually fluctuates
and it is more correct to define the average
speed as:
Average speed = distance covered ÷ time interval, or:
vave = v = d / ∆ t
The SI unit for speed is: meter per second (m/s).
A commonly used unit is the
kilometer per hour (km/h).
The USCS unit for speed is the mile per hour (mi/h),
used on American car speedometers .
It is easy to show that these units are related as
follows:
1 m/s = 3.6 km/h = 2.24 mi / h.
Example:
Using the same data as in the earlier example of
displacement, assume that the two objects covered d1
and d2 in 10 and 4 seconds, respectively
We conclude that:
v1 = 10 m / 10 s = 1 m/s v1 = 1 m/s, due east
v2 = 8 m / 4 s = 2 m/s v 2= 2 m/s, 30º north of east.
1.1.3 Acceleration:
Acceleration, ( a ), is the rate of change in velocity:
Acceleration = velocity change ÷ time interval, or:
Obviously, a is a vector quantity. In this equation, vi is the
initial velocity, and vf is the final velocity. The SI unit for
acceleration is meter per second squared (m/s2).
The magnitude of acceleration can be positive or
negative. A negative acceleration means that the
velocity decreases. Negative acceleration is also
called deceleration.
In our discussion, we refer to the three vectors:
d, v, and a, as the motion vectors.
1.2 Motion in One and Two Dimensions
1.2.1 Linear (or 1-D) Motion
1.2.1.1 Description
An object moving along a straight line is said to be in linear motion .
This is the simplest form of motion, and we deal with it in most of our
discussion of motion. A simple example of linear motion is a car moving
along a straight and Level road.
Assume that an object in linear motion is subjected to a
constant acceleration (a), covering a distance (d) in a time
interval (t). Let its initial and final speeds over this distance be
vi and vf . From this, we can derive the following important
equations of motion:
1.2.1.2 Acceleration of Gravity
An important example of linear motion is:: motion under the effect of the
Earth’s gravitational field. This field produces an acceleration of
gravity, g, that acts on all objects within it. g always points
downward toward the center of Earth. The value of g decreases
with altitude and its value at sea-level is:
When an object is in free fall, its motion can be described
by the above equations, replacing “a” with “g”.
1.2.2 Planer (or 2-D) Motion;
1.2.2.1 Description
Planer motion is motion that takes place within just one plane
We also call it two-dimensional (2-D) motion.
To solve planer motion problems,
the motion vectors are sometimes decomposed to components
in two directions (such as x and y). The components in each direction
are then treated as in linear motion. We will apply this approach later in our
study of the inclined plane.
1.2.2.3 Examples
1. Assume that an arrow is
shot horizontally from a
height (h) with a speed (v),
and that air resistance is negligible.
We can decompose the arrow’s motion into a vertical part,
which is free fall, and a horizontal part, which has constant
speed. Using the earlier equations of motion, we can then
say that:
2. A man swims across a
river with a velocity Vm,and the
velocity of the river’s downstream
current is (Vc) .Normally, Vm is
given relative to the river, and Vc is
given relative to land.
From these, we can calculate
the man’s velocity relative to land
as:
3. A man moves with a velocity V
m-s
on
board of a ship that travels at a velocity V
s-b
relative to a fixed bridge. We can calculate
the man’s speed as observed from the
bridge as :
Vm-b = Vm-s + Vs-b
Φ is the angle between Vm-s and Vs-b
. When Φ = 0º or 180º, the motion reduces
to linear motion as shown; and when Φ =
90º, the net velocity can be calculated using
the Pythagoras theorem.
Examples:
Information you might need:
d =1/2at2 +Vi t
Vf2 -Vi2 = 2ad
Vavg = Vi + Vf/ /2 = d/t
a = Vf -Vi / t
g = 10 m /s2
1m / s = 3.6km /h
F = m.a
d = v √(2h/g)
A100-kg crate is moved along in a linear path;
1-The crate is pushed a distance of 10m in 5 seconds. Its
average speed is;
(a) 1 m/s
(b) 2m/s
(c) 3m/s
(d) 4m/s
2- The crate is pushed to increase its speed from 3 m/s to 5
m/s. Its average speed is:
(a) 1 m/s
(b) 2m/s
(c) 3m/s
(d) 4m/s
3- If the crate is pushed to increase its speed from 1 m/s
to 3 m/s in 4-seconds, its average acceleration is :
(a) 1 m/s2
(b) 2 m/s2
(c) 0.5 m/s2
(d) 4 m/s2
4- If the crate is pushed with a force of 200 N , its
acceleration is :
(a) 1 m/s2
(b) 2 m/s2
( c) 0.5 m/s2
(d) 4 m/s2
5-Velocity is the same as:
(a)displacement
(b)deceleration
c)average speed
(d)directed speed
Lecture 3 & 4
2 -NEWTON’S LAWS:
2.1 Newton’s First Law of Motion
2.1.1 Definitions
2.1.1.1 Inertia and Mass:
Inertia is a natural concept that means : if the object
is at rest, it tries to remain at rest; and if it is moving,
it tries to continue moving.
Inertia is an object’s opposition to changing its
current state of motion.
An object’s inertia depends on the amount of matter
it contains: the more the matter, the more the inertia.
The quantity that describes the amount of matter in
an object is called “mass”
Mass is the quantity of matter in an object. It is also a
measure of an object’s inertia.
We use the symbol “m” for mass; and
its SI is the kilogram (kg).
2.1.1.2 Force:
We define force as a pull or push.
Force is what causes acceleration and motion.
Forces can be gravitational ,electric ,magnetic
,nuclear or, simply, muscular.
To fully know the effect of a force, we must know its
magnitude and direction. Therefore, force is a
vector quantity. We usually use the symbol F for
force. The SI unit for force is the Newton (N).
When more than one force act on an object, we often need
to calculate the net force acting on the object. The net
force is the VECTOR sum (or resultant) of the individual
forces:
Net force is also called unbalanced
2.1.1.3 Weight
Weight is the force acting on an object because
of gravity.
We use the symbol w for weight;
and its unit is the Newton (N) –
since it is a force. From its
definition, we note that weight is
proportional to the gravitational
acceleration (g). Weight w is also
proportional to the object’s amount
of matter (or mass m). Therefore,
we conclude: w = m × g
; a vector always pointing down
toward the Earth’s center.
2.1.1.4 Mechanical Equilibrium
When no net force acts on an object ( ΣF = 0 ), we say then
that the object is in mechanical equilibrium
From this, we conclude that mechanical equilibrium
is two types:
a)Static equilibrium : when the object does not move (v = 0).
b)Dynamic equilibrium : when the object moves with constant
velocity.
2.1.2 Statements of the 1st Law:
Newton’s 1st law of motion (also known as the inertia law)
states that:
When no net external force acts on an object, it remains
in a state of uniform motion.
Here, “uniform motion is motion with a constant velocity, v.
In other words, we may restate this law as follows:
When no net external force acts on an object, its
velocity remains constant.
From the earlier discussion of acceleration, we know that a
constant velocity means zero acceleration. Therefore, we may
also restate this law as:.
When no net external force acts on an object, its
acceleration remains zero
From the concept of mechanical equilibrium, we may again
restate Newton’s 1st law as:
When no net external force acts on an object, it is in
mechanical equilibrium.
The above four equivalent statements of
Newton’s 1st law are summarized in the
following table:
2.1.3 Spring-Effect Forces
2.1.3.1When a spring is stretched, it tries to
Contract and when compressed ,it tries to
expand. The spring’s force F is proportional
(but opposite to) the change in its length (∆x).
This is known as Hooke’s law,
and is written (in 1-D) as:
F = - k ·∆x
where k is a constant (unit: N/s2)
that indicates the spring’s stiffness
2.1.3.2 Support Force:
According to Newton’s 1st law,
the net force on the book is zero.
Since we know that this object is
acted upon by the gravitational
force (i.e., its weight) there must
be an equal and opposite
force,FN, to cancel it and make
the net force zero. This force is
called the “support” force
It is important to note that the support force is always
perpendicular to the surface on which the object
rests, which means that it is NOT NECESSARILY
vertical. It is vertical only when the object rests on a
horizontal surface.
The support force is
what gives the reading
of a weighing scale.
2.1.3.3 Tension
If a load hangs motionless
FN = W = m g
from a rope, it has zero
acceleration, which means
that there is zero net force
acting on it. Since we
know that the load is
acted upon by
the gravitational force,
there must be an equal
and opposite force, T, to
cancel it and make the net
T==W=mg
force zero. This force is
called “tension”
Example: In the figure below, a painter stands on a painting staging (H)
that hangs from two ropes attached to a high roof. The system is in static
equilibrium, which means:
2.2 Newton’s Second Law of
Motion
2.2.1 Statement of the 2nd Law
Applying a force on an object
produces acceleration. In the figure,
we see that increasing the force
produces more acceleration, and that
increasing the object’s mass causes
the acceleration to decrease.
Therefore, we conclude Newton’s
2nd law of motion:
An object’s acceleration is directly
Proportional to the net applied
force and inversely proportional
to the object’s mass.
From this, we note that:
1. The unit of force, Newton, is the
force needed to accelerate a 1-kg
mass by 1 m/s2.
2. The weight-mass relationship can
now be re-derived:
3. The 1st law is a special case of the
2nd law, with
Examples:
A 50- Kg barrel is pushed along a linear path:
1- If the barrel speed increases from 2m/s to 4m/s over a
distance of 3m, its acceleration is:
(a) 1 m/s2
(b) 2 m/s2
(c) 0.5 m/s2
(d) 4 m/s2
2-If the barrel is pushed with a net force of 50 N , its
acceleration is:
(a) 1 m/s2
(b) 2 m/s2
(c) 0.5 m/s2
(d) 4 m/s2
3- The normal force on the barrel is:
(a) 0 N
(b) 5 N
(c) 500 N
(d) 50 N
4-The measurement in a bathroom scale is caused by :
(a)Dynamic force
(b)tension force
( c) electric force
(d) support force
5-The measurements in a hanging scale is caused by;
(a)Dynamic force
(b)tension force
( c) electric force
(d) support force
6-If a moving car makes a sudden stop , the passengers
fall forward. This is explaained by:
(a) lnertia
(b) gravitation
(c) acceleration
(d) friction
2.2.2 Opposing Forces
Opposing forces are forces that oppose the normal
course of motion. In this subsection, we discuss
two such forces: friction between surfaces, and air
resistance.
2.2.2.1 Friction:
When we apply a force to slide one surface
against another, we feel an opposite force trying to
prevent the sliding. This force is called the force
of friction. No sliding will take place unless
the force we apply overcomes the frictional force.
Important Notes:
1. When we push a stationary object to slide, “static” friction pushes back
with an equal force: Ff . If we increase our push, Ff increases. Both forces
continue to increase until we can overcome the maximum frictional force, at
which point the object starts moving.
2. Once the object starts moving, the “dynamic” friction becomes less
than the “static” friction, and our excess pushing force would cause the object
to accelerate. The following figure shows a plot of friction versus applied force
where motion starts when the applied force is 50 N.
3. We may then decrease our force to just
cancel the “moving” frictional force, causing
the object to move with constant velocity (zero
acceleration), as in the example shown in the
adjacent sketch.
4. we note that an increase in the normal force
would act like adding glue between the two
surfaces. Thus, it is easier to push an empty
crate (less glue) than a crate full of books (more
glue). We conclude that friction is proportional to
the magnitude of the normal force:
Ff ∝ FN.
5.The last relationship can be converted to equality by introducing a
constant. μ is an empirical constant called the coefficient of friction. It
is dimensionless, and it gives the relative frictional values for different
pairs of surfaces.
Thus we have:
2.2.2.2 Inclined Plane
If an object of mass (m) rests on a ramp
of angle θ, its weight (w =m × g)can be
decomposed into two components, one
perpendicular to the surface ( ), and
one parallel to it (
From the adjacent diagram, we have:
We saw earlier that the magnitude of the normal force
always equals
Any object falling in normal (non-vacuum)
conditions is subject to air resistance. Air
resistance (FR) arises from the bombardment
of the falling object with air molecules, which
produces an opposing force from the air
molecules on the object. The following factors
increase bombardment rate and, consequently,
air resistance:
1. Object’s cross-sectional area FR ∝ A.
2. The square of the object’s speed: FR ∝ v2
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