Download Slide 1 - O6U E-learning Forum

‫بسم هللا الرحمن الرحيم‬
‫السالم عليكم ورحمة هللا‬
‫وبركاته‬
‫أ‪.‬م‪.‬د‪/‬هالة مصطفى احمد‬
‫استاذ مساعد الفيزياء‬
‫ميثاق المحاضرة‬
‫‪covenant‬‬
Overall aims of course:
Aim of course is to provide the students with the
principle knowledge about the UNITS AND
DIMENTIONS, NEWTON's LAW OF MOTION, WORK
AND ENERGY , also this course will provide the
students by the valuable information about the bio
ELASTICITY,FLUIDS SIMPLE HARMONIC MOTION and
THERMODYNAMICSthat will enable them to gain the
skills in the field of experimental physics and so push
them for constructing and developing a simple tools
depending on that basic knowledge.
‫الفيزياء ‪Physics‬‬
‫المخرجات التعليمية المستهدفة من مقرر الفيزياء‬
‫‪INTENDED LEARNING‬‬
‫)‪OUTCOMES OF COURSE(ILO’S‬‬
Intended learning outcomes of course(ILO’s)
1-Define the basic theory of physics.
2-Understanding of physical
phenomena in physical sciences.
3-Able to specialize within the
various theoretical and
experimental fields of physics.
4-Describe various aspects of
physics.
5-Application of heat transfer
Intended learning outcomes of course(ILO’s)
6-Know the mechanisms of thermal
energy
7-Use the applications of electricity
8-Explain the Stress &Strain can be classified
9-Arrange the Mechanical Tests
10-Use Hooks Low
11-Classify Elastic coefficients
Distribution of Physics Syllabus
First Term- First Year
Weekly plan: 3 Hours
Assessment schedule:
Assessment 1:
Quiz /end chapter(1-2-3)/week 5
Assessment 2:
One search/half year/week 8
Assessment 3:
Sheet practical exam/end practices/week 10
Assessment 4:
Midterm/midyear )/week 10
Assessment 5:
Final exam/first term year)/week 16
Weighing of Assessments
Final – Exam
60 %
Mid-Term Exam
15 %
Practical Exam
10%
Copy book attendance 5%
Sheets
5%
Research
5 %
-------------------------------------------Total
100 %
Learning materials
1-Text book:
• Serway R. & Jewett J., “Physics for Scientists and
Engineers” 6th Ed. Thomson Brook/Cole 2004.
• David Halliday, Robert Resnick, Jearl Walker,
Fundamentals of Physics Extended, 8th edition,
ISBN: 978-0-471-75801-3 Wiley 2007
2-Useful Web sites:
www.Science physics.org
www.Physics.auburn.edu
www.yahoo.com/science/physics
‫‪Introduction‬‬
‫• علم الفيزياء هو علم تجريبي يهتم بكشف أسرار‬
‫الطبيعة‪ ،‬فكل شيء نعرفه عن هذا الكون وعن القوانين‬
‫التي تحكمه تم التوصل إليها عن طريق القياسات‬
‫‪Science of‬‬
‫والمالحظات ألي ظاهرة‬
‫‪measurements‬طبيعية‪ .‬ويعرف علم الفيزياء أيضا‬
‫بأنه علم القياس‬
‫• يقول العالم الشهير كلفن "عندما تستطيع قياس ما‬
‫تتكلم عنه وتعبر عنه باألرقام فإنك إذا تعرف شيئا عنه‪،‬‬
‫ولكنها عندما ال تستطيع التعبير عنه باألرقام فإن‬
‫معرفتك في هذه الحالة‬
‫• غير كافية ولكن تعتبر البداية"‪.‬‬
‫‪UNITS AND DIMENTIONS‬‬
‫‪1- The physical quantities:‬‬‫‪Physical quantities are the building blocks of the physical science.‬‬
‫‪The laws of physics are expressed as relationships between‬‬
‫‪the physical quantities.‬‬
‫لتعريف الكمية الفيزيائية ‪Physical Quantity‬فإنه يجب أوال أن نعرف طريقة قياس‬
‫هذه الكمية أو طريقة حسابها رياضيا ً من كميات أخرى‪.‬‬
‫مثال ‪:‬‬
‫المسافة والزمن بواسطة وصف الطريقة التي يمكن أن نقيس كالً منهما‪ ،‬وبالتالي يمكن‬
‫تعريف سرعة جسم متحرك بواسطة حساب حاصل قسمة المسافة على الزمن‪ .‬في هذه‬
‫الحالة فإن كالً من المسافة والزمن هما كميتان فيزيائيتان أساسيتان بينما السرعة فهي‬
‫كمية‬
‫فيزيائية مشتقة ‪.Derived Physical Quantity‬‬
Units
• Physical quantities have two types
‫• الكميات الفيزيائية لها نوعان‬
• 1-Fundamental quantities.
‫كميات اساسية‬
• 2-Derived quantities.
‫كميات مشتقة‬
1-The fundamental quantities
(The length (L), the mass (M), and the time (T)).
: ‫الكميات األساسية الثالثة‬
L ‫طول‬
M ‫كتلة‬
T ‫الوقت‬
2-Derived quantities
which are expressed in terms of the
fundamental quantities.
‫• كميات التي يتم التعبير عنها من حيث الكميات‬
.‫األساسية المشتقة‬
2-Derived quantities. ‫كميات مشتقة‬
Examples of derived quantities:Examples of the physical quantities are speed,
displacement, velocity, acceleration, linear
momentum, force, angular velocity, angular
momentum, torque, work, energy, temperature,
volume, density, electric charge, electric potential,
electric current,
،‫ واالزحة‬،‫أمثلة على الكميات الفيزيائية المشتقة هي السرعة‬
،‫ عزم الدوران‬،‫ السرعة الزاوية‬،‫ القوة‬،‫ العجلة‬،‫والسرعة‬
‫ تيار‬،‫ الشحنة الكهربائية‬،‫ الحجم الكثافة‬،‫درجة الحرارة‬،‫الطاقة‬
.‫كهربائي‬
Three systems of units are most commonly
used in science and engineering
‫انظمة الوحدات‬
(1) The International System of Units (SI system). ‫النظام الدولي‬
In this system we have the following units:the length has unit of meter
(m),
the mass has unit of kilogram
(kg),
the time has unit of second
(S).
(2) The Gaussian System of Units (CGS system). ‫في المعمل‬
the length has unit of centimetre (cm),
the mass has unit of gram (gm),
the time has unit of second
( s ).
(3) The British system of units (FPS system).
the length has unit of foot
(ft),
the mass has unit of pound......
(p),
the time has unit of second
(s).
‫‪Some useful conversions‬‬
‫• تعتبر وحدة قياس المسافة (الكيلومتر) كبيرة في بعض‬
‫األحيان فمثالً لقياس طول غرفة الدراسة أو قياس مسافة‬
‫عرض الشارع فإنه يمكن استخدام وحدات مشتقة مثل المتر‬
‫أوالسنتمتر أو الميليمتر‪ ،‬أما في حالة قياس مسافات ذرية‬
‫فإننا نستخدم وحدات أصغر مثل األنجسترم‪ .‬الجدول التالي‬
‫يوضح قيمة وحدات المسافة المشتقة بالمتر‪.‬‬
‫‪Prefixes for Power of ten‬‬
‫• كثيرا ً ما تكون الوحدات األساسية (الكيلومتر‬
‫والكيلوجرام والثانية) إما صغيرة أو كبيرة نسبة لما‬
‫نقوم بقياسه من كميات فيزيائية لذا فقد تم تسمية‬
‫وحدات عملية أخري موضحة في الجدول التالي‪:‬‬
Dimensions
• 1-Fundamental quantities.
‫• أي كمية فيزيائية لها وحدة يكون لها ابعاد‬
• 2-Derived quantities.
Dimensions
1-Fundamental quantities
NOTE:
[L] .[L]= [L2]
[L] +[L]= [L]
[L] -[L]= [L2]
[L] /[L]= 1
Dimensions
2-Derived quantities
1-velocity
[v]=dx/dt
[v] =L/T
ms-1
2- acceleration
a=dv/dt
[a] =L/T/T
=LT-2
ms-2
Dimensions
2-Derived quantities
3-Force
F=ma
[F] =MLT-2
‫الكتلة=القوة‬x‫العجلة‬
kgms-2 = Newton
4- Work
W=F.S
[W]=MLT-2.L=ML2T-2
‫الزمن‬/‫العجلة =السرعة‬
kgm2s-2 = joul
Dimensions
2-Derived quantities
5-Torque
t=F.d
[t] =MLT-2.L
[t] =ML2T-2
kgm2s-2
6- Pressure
P=F/A
[P]=MLT-2/L2=ML-1T-2
Kgm-1s-2 = pa
Dimensions
2-Derived quantities
7-Momentum
p=mv
[p] =MLT-1
kgm1s-1
8- Angular momentum
=mvr
=MLT-1.L=ML2T-1
Kgm2s-1
Dimensions
2-Derived quantities
9-Power
P=W/t
[P] =ML2T-2/T
[P] =ML2T-3
kgm2s-3 =W
10- Angular velocity
ω =v/r
[ω]=LT-1/L=L
Rad /s
Dimensions
2-Derived quantities
11-Potential energy =work
[P] =ML2T-2
kgm2s-2 =J
12-Kinetic energy =work
[K] =ML2T-2
kgm2s-2 =J
Dimensions
2-Derived quantities
13-Electric potential =work/charge
[V] =ML2T-2/Q
=Q-1ML2T-2
C-1kgm2s-2
14-Electrical resistance
[R] =Electrical potential/electric current
[R]=Q-1ML2T-2/Q/T
C-2kgm2s-1
Dimensions
2-Derived quantities
15-Surface tension
[T] =F/l
[T]=ML2T-2/L
=MT-2
Kg.s-2
16-Area
[A] =[L2]
m2
Dimensions
2-Derived quantities
17-volume
[V] =[L3]
m3
18-Spring constant
[K] =F/X
=MLT-2/L
MT-2
Dimensions
2-Derived quantities
19-frequency
[f] =1/T
[f] =T-1
S-1
20-Angular acceleration
[α] =a/r
=LT-2/L
=T-2 rad/s2
Dimensional analysis
Uses of Dimensions analysis:
1-Check the correction of any equation.
‫اختبار صحة المعادلة‬
2-To deduce the equation (Laws).
‫استنتاج القوانين‬
‫أي كمية فيزيائية لها وحدة يكون لها ابعاد‬
Derive the dimensions of a physical quantity
Derivation of physical formulas and
expressions. Check the correctness of
formula or expression. We use the fact
that in equations and formulas the left
hand side (LHS) must have the same
dimensions as the right hand side (RHS) .
Dimensional ‫للتأكد من صحة المعادالت والعالقات‬
‫تستخدم تحليل األبعاد الرياضية المشتقة في‬Analysis
‫الفيزياء حيث أن وحدة الطرف األيمن للمعادلة يجب أن‬
‫ وإال فإن المعادلة‬،‫يساوي وحدة الطرف األيسر للمعادلة‬
.‫غير صحيحة‬
Important Derived Quantities
SHEET (1) PROPERTIES OF MATTER
(2015-2016)
1-The potential energy function for the force in a diatomic molecule
is given by U=(a/ X4)- ( b/X2)Where x is the separation between
the two atoms the dimensions of a and b are constant.
a)ML6T2 , ML4T2 b) ML2T2, MT2
c) ML3T2, MLT2 d) ML3T , ML1T2
e)non of these.
2-The quantity a/volume has the dimensions of pressure .Then (a)
has the dimensions formula:
a)M1L2T2
b) ML2T-2 c) M1L3T-2 d) M1L5T2 e) M-1L2T-2
3-Given that : α = a/1-bω where α is angular acceleration and ω is
the angular velocity the dimensions of a are -----------and the
dimensions of b are---------------
SHEET (1) PROPERTIES OF MATTER
(2015-2016)
4-Given that E=mgh/a-bω2 where E energy, m mass gravitational
acceleration h height and ω angular velocity. The dimensions of a
are ----------------and the dimensions of b---------------------5- The dimensions of the spring constant k is:
a)M-1L-2T6
b) M6L-1T1 c) M -1L-1T-1 d) M1L6T2 e) MT-2
6- The dimensions of the potential energy is:
a) L2M1T-3
b) L-3M-1T2 c) L2M1T-2 d) L-2M-1T2
e) L-3M-1T-2
7- The dimensions of the angular kinetic energy is:
a) M LT1
b) M L3T2
c) M L2T-2
d) M3 L1T2
SHEET (1) PROPERTIES OF MATTER
(2015-2016)
8- The SI unit of angular momentum is ---------------and its dimension
is-----9- The SI unit of power is ---------------and its dimension is------10- The SI unit of universal gravitational constant G is ---------------and
its dimension is--11- The SI unit of angular velocity is----------and its dimension is------12-The dimensions of the Power (F x v) is:
a) M1 L1 T-2
b) M1 L2T-2 c) M1 L1T-3
d)M1L2T-3
13-During a short interval of time, the speed v in m/s of an
automobile is given by v = at 2+bt 3, where the time it is in
seconds. The units of a and b are respectively:
a) ms2; ms4
b) S3/m;S4/m c) m/s3; m/s4 d) m/S2;m/s4
SHEET (1) PROPERTIES OF MATTER
(2015-2016)
14- The dimensions of the coefficient of the
surface tension ( T= F / L) is
.a) MT-2 b) M1 LOT-1 c) M1 L1T-1.
d)· M1 LOT-3
15- The dimensions of the Bulk modulus ∆p/(∆V/V) is:
a)M1L-1T2 b) M1L-3T-3 c) M -1L-2T3 d) M L-1T-2
SHEET (1) PROPERTIES OF MATTER
(2015-2016)
16- The equation of state of some gases can be expressed as
(P + a/v2 )(V - b) = RT, where the symbols have their usual
meaning ( P: pressure, V: volume, R: universal gas
constant, T: temperature). The dimension of "a" is:
a)ML-2T2
b) ML5T-2 c) T6
d) M L6T-2 e) M2 L-2T2
f)non of these
17- Check the following equation x +vot+1/2at.
18-Apply the dimensional analysis to derive an expression
for the frequency of vibration (f) of separated wire of
length (L) mass per unit length (µ) and under tension
(F).fαLx fαµy
fαFz
L length of wire ,µ =M/L (liner density) ,F tension in the wire.
SHEET (1) PROPERTIES OF MATTER
(2015-2016)
19-Show whether or not the following physical relations
are correct from the dimensional point of view.
a)Force = mass x acceleration
b)Torque = energy x time
c)Angular momentum = force x time
20-Newtons law of universal gravitational is represented
by F = G m1m2/r2 where F is the magnitude of
gravitational forces exerted between two masses m1
and m2 and r is distance between the centers of the
two masses. What are the units and dimensions of
the proportionality constant G?
‫ميثاق أخالقيات المهنة‬
Motion in Uniform Circular Motion
One of the important motions in two dimensions (motion
in plane) is the uniform circular motion. In which a particle
moves on the circumference of a circle of constant radius
with uniform linear speed. When an object moves in uniform circular
motion, its linear speed is constant, but its velocity vector v is
continuously changing in direction.
Because the velocity is a vector quantity, there are two ways in which
acceleration can be produced: (by a change in the magnitude of the
velocity (this produces linear acceleration) and by a change in direction of
the velocity (this produces centripetal acceleration).
‫ فيه الجسيمات؟‬.‫احد من االقتراحات الهامة في بعدين (الحركة؟ في الطائرة) هي حركة دائرية موحدة‬
‫ عندما ينتقل الكائن في‬.‫التحركات على محيط دائرة نصف قطرها ثابت؟ مع سرعة خطية موحدة‬
‫ ولكن لها ناقل السرعة ضد تتغير باستمرار في‬،‫ وسرعته الخطية ثابتة‬،‫حركة دائرية موحدة‬
.‫االتجاه‬
‫ (عن طريق تغيير‬:‫ هناك نوعان من الطرق التي تسارع يمكن أن تنتج‬،‫ألن السرعة هي كمية متجهة‬
. )‫في حجم سرعة (وهذا ينتج تسارع الخطي) وتغيير في اتجاه سرعة (وهذا ينتج تسارع الجاذبية‬
‫من الممكن أن يتحرك جسم على مسار دائري بسرعة خطية ثابتة ‪linear constant‬‬
‫‪speed‬قد يخطر لنا اآلن أن العجلة في هذه الحالة تساوى صفراً‪ ،‬وذلك ألن السرعة ‪.‬‬
‫ثابتة‪ ،‬وهذا غير صحيح ألن الجسم يتحرك على مسار دائري لذا توجد عجلة‪ .‬ولشرح‬
‫ذلك نحن نعلم أن السرعة كمية متجه‪ ،‬والعجلة هي عبارة عن كمية متجه ألنه ا تساوى‬
‫معدل التغير في السرعة بالنسبة للزمن‪ ،‬والتغير في السرعة قد يكون في المقدار أو في‬
‫االتجاه‪ .‬وفي حالة حركة الجسم على مسار دائري فإن العجلة ال تؤثر على مقدار السرعة‬
‫إنما تغير من اتجاه السرعة‪ ،‬ولهذا فإن‬
‫الجسم يتحرك على مسار دائري وبسرعة‬
‫ثابتة‪ .‬يكون متجه السرعة دائما عمودي ا ً‬
‫على نصف القطر وفى اتجاه المماس عند‬
‫أية نقطة على المسار الدائري كما في‬
‫‪ .‬الشكل‬
For an object moving in uniform circular motion of radius
R with constant linear speed v, there is centripetal
acceleration only. This acceleration is given by:
a = v2/R
The centripetal acceleration is always directed to the centre.
The frequency v: is the number of complete revolutions (cycles)
per unit time v= 1/T Since the body makes an angle of 2π in one
complete cycle then:
ω= 2 π /T
The angular velocity: In the circular motion the angular velocity
is defined as the rate of consuming angle. If the body makes an
angle θ in time t :
ω= θ /t
The period T: It is the time for one complete cycle or one
complete rotation.
In one complete cycle the body moves a distance of 2πR.
Therefore the linear speed v is given by:
v =2 π R / T
From this we see that:
v=ωR
The relation between the centripetal acceleration and the'
angular speed is now given by:
a = ω2 R
∆v/∆r = v /r
∆v = v/r∆ r
A particle moving in a circle of radius r with constant speed v is
in uniform circular motion
Divide both sides by ∆t
∆v/∆t = v∆r /r∆t
ac = v2
r
If a particle moves .along a curved path in such a way that both the magnitude and
the .direction of v change in time, then the particle has an acceleration vector. that
can. be described by
two component· vectors: (1) a radial component vector a, that
causes the change in direction of v and "(2) a tangential . Component vector at
that causes the change in magnitude of v.
The magnitude of a, is v2/r, and the magnitude of at is
dlvl/dt.