June 2010
Chapter 1
General Principles
) ‫( قذ ٌكٌٕ غٍش يقشس ثبنًُٓح‬
،‫يزكشاد ششذ ٔرًبسٌٍ يحهٕنخ‬
ِ‫ايزحبَبد عبثقخ نهؼذٌذ يٍ انًٕاد أدَب‬
ِ‫يزبحخ يدبَب ًا ػهى انًٕقؼٍٍ انًزكٕسٌٍ أدَب‬
‫انؼدٍت أٌ ثؼط انُبط‬
.‫ٌفعهٌٕ يٍ ٌكزة ػهٍٓى‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
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June 2010
Newton’s three laws of motion:
First law: A particle originally at rest, or moving in a straight line with
constant velocity, will remain in this state provided the particle is not
subjected to an unbalanced force.
Second law: A particle acted upon by an unbalanced force F experiences
an acceleration a that has the same direction as the force and a magnitude
that is directly proportional to the force.
F=ma
Third law: the mutual forces of action and reaction between two particles
are equal, opposite, and collinear.
Newton’s law of gravitational attraction:
F
m m
 G 12 2
r
Mutual
‫ رجبدنى‬،‫يزجبدل‬
Particle
‫خغٍى‬
principle
‫ قبػذح‬،‫يجذأ‬
collinear
‫ػهى َفظ انخط‬
universal
‫ ػبو‬،ًَٕ‫ك‬
evidence
‫ شبْذ‬،‫ دنًل‬،‫ثٍُخ‬
Where:
F = force gravitation between the two particles
G = universal constant of gravitation, according to
experimental evidence, G = 66.73 (10-12) m3/(kg . s2)
m1, m2 = mass of each of the two particles
r = distance between the two particles
W
 mg
ٍ‫ال رشض ثأقم ي‬
.‫انزًٍض انًطهق‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
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June 2010
Units of measurement:
the international system of units:
‫اثزل كم يب‬
‫رغزطٍغ نكم شًء‬
.ُّ‫أَذ يغئٕل ػ‬
rules for use:
1. A symbol is never written with a plural s, since it may be confused with
the unit for second (s).
2. symbols are always written in lowercase letters, with the following
exceptions: symbols for the two largest prefixes shown in Table 1-2,
giga and mega, are capitalized as G and M, respectively; and symbols
named after an individual are also capitalized, e.g., N.
3. quantities defined by several units which are multiples of one another
are separated by a dot to avoid confusion with prefix notation, as
indicated by N = kg . m/s2 = kg . m . s-2, Also, m . s (meter-second),
whereas ms stands for (milli-second).
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
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June 2010
4. the exponential power represented for a unit having a prefix refers to
both the unit and its prefix. for example, N 2  N 
 N  N
2
likewise, mm2 represents (mm)2 = mm.mm.
5. physical constants or numbers having several digits on either side of the
decimal point should be reported with a space between every three
digits rather than with a comma; e.g., 73 569.213 427. In the case of
four digits on either side of the decimal, the spacing is optional; e.g.,
8537 or 8 537. furthermore, always try to use decimals and avoid
fractions; that is, write 15.25 not 15 14 .
6. when performing calculations, represent the numbers in terms of their
base or derived units by converting all prefixes to powers of 10. The
final result should then be expressed using a single prefix. Also, after
calculation, it is best to keep numerical values between 0.1 and 1000;
otherwise, a suitable prefix should be chosen. for example,
50 kN  60nm
ْٕ ‫اخؼم انزًٍض‬
.‫ػاليزك انًغدهخ‬
 50 (103) N  60 (109 ) m



 3000 106  N  m  3 103  N  m  3 mN  m




7. compound prefixes should not be used; e.g. ks (kilo-micro-second)
should be expressed as ms (milli-second) since 1 ks = 1 (103) (10-6) s =
1(10-3) s = 1 ms.
suitable
exponential
refer to
furthermore
‫ يالئى‬،‫يُبعت‬
‫أط‬
‫ٌؼٕد إنى‬
‫ػالٔح ػهى رنك‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
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June 2010
8. With the exception of the base unit the kilogram, in general avoid the
use of a prefix in the denominator of composite units. for example, do
not write N/mm, but rather kN/m; also, m/mg should be written as
Mm/kg.
9. although not expressed in multiples of 10, the minute, hour, etc., are
retained for practical purposes as multiples of the second. furthermore,
plane angular measurement is made using radians (rad). In this book,
however, degrees will often be used, where
180
denominator
‫يقبو‬
multiple
‫يعبػف‬
significant
‫ كجٍش‬،‫يٓى‬
 
rounding off numbers:
 if the n + 1 digit is less than 5, n + 1 digit and others following it are
dropped. For example, 2.326 and 0.451 round off to n = 2 significant
figures would be 2.3 and 0.45.
 if the n + 1 digit is equal to 5 with zeros following it, then round off the
nth digit to an even number. For example, 1.245 (10 3) and 0.8655
rounded off to n = 3 significant figures become 1.24 (10 3) and 0.866.
 if the n + 1 digit is greater than 5 or equal to 5 with any nonzero digits
following it, then increase the nth digit by 1 and drop the n + 1 digit and
others following it. For example, 0.723 87 and 565.500 3 rounded off to
n = 3 significant figures become. 0.724 and 566.
‫ٔظغ انهًغخ األخٍشح ػهى ػًهك‬
.‫ثًثبثخ الربج انزي ٌكهم َدبحك‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
C++, Java, MATLAB, Data Structures, Algorithms, Discrete, Digital Logic, Concepts, Databases, Software
English 123, 162, 221, TOEFL, Numerical Methods, Economy, Supply Chain
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June 2010
a ) m / ms 
1m
103 s
 103
b)  km  10 6. 103
c) ks / mg
103 s

103 g
m  103
103 s

10 6 kg
m / s  km / s
 mm
m
 109
s / kg
represent
combination
 Gs / kg
ٍ‫ٌؼجش ػ‬
‫ يدًٕػخ‬،‫إرحبد‬
appropriate ‫ػهى ٔخّ انزقشٌت‬
‫ يقذيخ‬،‫ثبدئخ‬
prefix
‫انًُبفغخ انحقٍقٍخ دائًب يب‬
ّ‫ركٌٕ ثٍٍ يب قًذ ثفؼه‬
.ّ‫ٔيب أَذ قبدس ػهى فؼه‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
C++, Java, MATLAB, Data Structures, Algorithms, Discrete, Digital Logic, Concepts, Databases, Software
English 123, 162, 221, TOEFL, Numerical Methods, Economy, Supply Chain
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June 2010
a ) 8653 ms  8653  103
b) 8368 N
c) 0.893 kg
s  8.653 s
 8.368 kN
same
‫إعالن يهمك‬
‫االيزحبَبد انغبثقخ َٕٔربد انششذ‬
‫ٔانًغبئم انًحهٕنخ يزٕفشح ػهى انًٕقغ‬
eng–hs.com, eng-hs.net
represent
appropriate
prefix
ٍ‫ٌؼجش ػ‬
‫يُبعت‬
‫ يقذيخ‬،‫ثبدئخ‬
ٕ‫انزيٌ ٌغؼٌٕ دائًب َح‬
ٌٕ‫انزًٍض ٔاألفعم ٌصجح‬
.ٌٍ‫رهقبئٍب يثال نآلخش‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
C++, Java, MATLAB, Data Structures, Algorithms, Discrete, Digital Logic, Concepts, Databases, Software
English 123, 162, 221, TOEFL, Numerical Methods, Economy, Supply Chain
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June 2010
( 204 mm) (0.00457 kg ) / (34.6 N )

204  103  0.00457 / 34.6 m . kg / N

26.9  106

26.9
m . kg / N
m . kg / N
evaluate
significant
figure
appropriate
prefix
ٍ‫ٌؼجش ػ‬
‫ كجٍش‬،‫يٓى‬
‫ ػذد‬،‫سقى‬
‫يُبعت‬
‫ يقذيخ‬،‫ثبدئخ‬
‫انكثٍش يٍ انؼًم اندٍذ‬
ٍ‫ٌعٍغ ثغجت انؼدض ػ‬
.‫ثزل يب ْٕ أكثش قهٍال‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
C++, Java, MATLAB, Data Structures, Algorithms, Discrete, Digital Logic, Concepts, Databases, Software
English 123, 162, 221, TOEFL, Numerical Methods, Economy, Supply Chain
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June 2010
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
C++, Java, MATLAB, Data Structures, Algorithms, Discrete, Digital Logic, Concepts, Databases, Software
English 123, 162, 221, TOEFL, Numerical Methods, Economy, Supply Chain
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June 2010
a)
200
kN 2
 (200  103 ) 2
N2
 40  109
N2
 40  103
kN 2
 0.040
b) (0.005
MN 2
mm) 2
 (0.005  10 3 ) 2
 25.0  10 12
m2
m2
evaluate
‫ ٌحغت‬،‫ي َّيًو‬
‫ُيق‬
significant
‫ كجٍش‬،‫ْبو‬
figure
‫ ػذد‬،‫سقى‬
appropriate
‫يُبعت‬
prefix
‫ يقذيخ‬،‫ثبدئخ‬
 25.0 m 2
c) (400
m)3
 64  10 6
 0.064
m3
km 3
‫اصسع ثزسح انشغجخ فً ػقهك ٔعٕف‬
‫رشكم َٕاح راد قٕح ردزة إنٍّ كم‬
.‫شًء ٌحزبخّ نزحقٍق َدبحك‬
) ًَٔ‫ أٔ ثبنجشٌذ االنكزش‬SMS ‫ْذٌخ قًٍخ ػُـذ انزُجٍّ ػهى كـم خطـأ ( ثشعبنخ‬
Statics, Strength, Dynamics, Mechanical Design I, II, Vibrations, Survey, Management, Structural Analysis I, II, Heat
C++, Java, MATLAB, Data Structures, Algorithms, Discrete, Digital Logic, Concepts, Databases, Software
English 123, 162, 221, TOEFL, Numerical Methods, Economy, Supply Chain
www.eng-hs.net & www.eng-hs.com ٍٍ‫ ششذ ٔيغبئم يحهٕنخ يدبَب ًا ثبنًٕقؼ‬info@eng-hs.com 9 4444 260 ٌ‫حًبدح شؼجب‬.‫و‬