PHYSICS-I LECTURE 1
KARADENIZ TECHNICAL
UNIVERSITY
DEPARTMENT OF MECHANICAL
ENGINEERING
FALL 2021-2022
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WELCOME TO PHYSICS I
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Course Rules
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I’II make important class announcement via UZEM MESSAGE, please check
your UZEM MESSAGE OFTEN !!!
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I’II post the lecture notes online before the lecture..
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Exam Grading: Midterm Exam (%50), Final Exam (%50)
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You will need to buy a scientific calculator for trigonometric calculations.
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How to become successful in physics I course?
-You should read the textbook before or after the lecture.
-You should review the lecture notes periodically after the lecture . I expect you
to do problems after the lecture on your own until you understand it.
- Work on recommended problems.
-Attend the class OR listen the recorded video lectures!
COURSE MATERIAL
1) Physics For Scientist and Engineers, SERWAY &
th
JEWETT 9 Edition.
2) Principle of Physics (David HALLIDAY, Robert
RESNICK, Jearl WALKER)
3) Physics for Scientists & Engineers, Douglas C.
Giancoli.
4) University Physics (Hugh D.YOUNG and Roger A.
FREEDMAN)
** This term, we will cover from chapter 1 to chapter
11 in textbook number 1).
** If you want to read extra materials, you can get
textbooks number 2), 3)and 4).
Vocabulary of Chapter 1
measurement= olçüm
unit=birim
significant figures=anlamli rakamlar
Round up= bir sayiyi yukari yuvarlamak
Experiment =deney
Calculation= hesaplama
Decimal number=ondalik sayi
digit=rakam/hane
OUTLINE
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Measurements & Units
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Signifcant Figures
Measurements and Units
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All physical quantities are
measured in its own units.
In this course we’II use SI
(International System) units.
Three fundamental quantities
used in mechanics: Length,
Time and Mass.
Quantity Unit
Unit
Symbol
Length meter
m
Time
second s
Mass
kilogram kg
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Measurements and Units (Continued)
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When dealing with very small or large numbers, it is convenient to
use prefixes.
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Signifcant Figures
Significant figures are a method used in calculations to show the precision of
numbers.
Rules for Significant Figures (Sig. Fig.):
1) All nonzero digits are significant.
2) Zeros between significant digits count as significant.
Examples
Number
Significant figure
60.3
205,030
8.32
2006
1050
3
5
3
4
3
3) If the number does not have a decimal point, zeros at the end of the number
are not significant.
4) Zeros at the end of a number are significant only if they are to the right of the
decimal point.
EXAMPLES
Number
0.00124
Significant
figure
3
200
1
600.
3
600
1
600.0
4
0.003
0.0030
0.0050720
1
2
5
How many significant figures are there in this number?
5 sig. figures
0.0040730
Leading zeros not
significant
This zero is significant if there is
a decimal point
This zero is significant,because between non-zeros
Significant numbers are written in red in the table.
Significant Figures(Continued)
NOTE!! When using a calculator, all digits on your
calculator are NOT significant!!
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Here we discus how to round a large/small number to
a significant figure.
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Rules for rounding numbers:
1) If the numbers ends in something greater than 5,
then you round up.
2) If the number ends in something less than 5, then
you keep the last digit the same.
3) If the number ends in a perfect 5 you round to the
nearest even number.
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Example: Round 2.46 to 2 significant figure.
2.46
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6 is bigger than 5: Round up last digit
2nd significant figure
2.46 becomes 2.5
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Ex: Round 3476 to 3 significant figure.
3476
3480
6 is bigger than 5: Round up last digit
3
rd
significant figure
Significant Figures(Continued)
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Let’s try couple of examples
Original Number
Number of
Significant Figures
Wanted
1) 24.03501
3
2) 0.03248
2
3) 36.50000000000 2
4) 36.5
2
37.5
2
5) 275
2
6) 0.002355
3
7) 2.057
3
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Rounded
Number
24.0
0.032
36
36
38
280
0.00236
2.06
Ex: Round 205.349 from 1 to 4 significant figure.
205.349 becomes 200
1 sig. Figure
205.349 becomes 210
2 sig. Figure
205.349 becomes 205
3 sig. Figure
205.349 becomes 205.3
4 sig. Figure