1. Introduction
Which of the following professionals (專業人仕) need knowledge (知識) of physics?
Medical Doctor (醫生)
Accountant (會計師)
Civil Engineer (土木工程師)
Lawyer (律師)
Car Designer (汽車設計師)
Salesman / Saleslady (售貨員)
Physicist (物理學家)
Clerk (文員)
Chemist (化驗師)
Waiter / Waitress (待應)

2. Introduction Civil Engineer (土木工程師) Car Designer (汽車設計師)
Which of the following professionals (專業人仕) need knowledge (知識) of physics?
Medical Doctor (醫生)
Civil Engineer (土木工程師)
Car Designer (汽車設計師)
Physicist (物理學家)
Chemist (化驗師) 2

3. What is PHYSICS? * Branch (分支) of science, …
* Study of atoms (原子), molecules (分子), … to
earth (地球), sun (太陽), …
* Study of force (力) , energy (能量) , …
* Study the laws of nature (自然定律), …
* Experiments (實驗), …

4. Physical Quantities (物理量)
Distance (距離)
Time (時間)
Mass (質量)
Temperature (溫度)
Volume (體積)
Density (密度)
......

5. Unit (單位) Physical Quantity (物理量) Unit (單位) Symbol (符號) Length (長度)
metre (米) m
Time (時間)
second (秒) s
Mass (質量)
kilogram (千克) kg

6. Which of the following is the correct SI unit of time?
Class Exercise 1.1
Which of the following is the correct SI unit of time?
year
month
minute
D. second 6

7. Which of the following is the correct SI unit of time?
Class Exercise 1.1
Which of the following is the correct SI unit of time?
year
month
minute
D. second 7

8. Class Exercise 1.2
Which of the following symbols represents the correct SI unit of mass? g kg Kg KG 8

9. Class Exercise 1.2
Which of the following symbols represents the correct SI unit of mass? g kg Kg KG 9

10. Sub-unit giga G 109 mega M 106 kilo k 103 centi c 10-2 milli m 10-3
Prefix (字首)
Symbol (符號)
Index
Multiple
giga G
109
1,000,000,000
mega M
106
1,000,000
kilo k
103
1,000
centi c
10-2
1/100
milli m
10-3
1/1000
micro μ
10-6
1/1,000,000
nano n
10-9
1/1,000,000,000

11. Convert the following quantities. 20 km = ______________ m
Class Exercise 1.3
Convert the following quantities.
20 km = ______________ m
29 ns = ______________ s
0.27 g = ______________ kg
612 nm = ______________ m
Ms = ______________ s
34.5 g = ______________ g 11

12. Significant Figures (有效數字)
All measured (測量) quantities have unavoidable (不可避免) error (誤差).
The more number of significant figures, the more accurate (準確) is the measurement.
All non-zero figure (1, 2,…9) is significant.
“Zero” may be or may not be significant.

13. No. of Significant Figures
Examples:
Value
No. of Significant Figures 5 1 51
0.67
0.0021 2
123
32.1
4.56 3
2468
1.002 4

14. (a) 567 (b) 2.68 (c) 0.000 012 3 (d) 100.123 (e) 21 Class Exercise 1.4
Which of the following quantities are expressed in 3 significant figures?
(a) 567
(b)
(c)
(d)
(e) 21

15. (a) 567 (b) 2.68 (c) 0.000 012 3 Class Exercise 1.4 (d) 100.123 (e) 21
Which of the following quantities are expressed in 3 significant figures?
(a) 567
(b)
(c)
(d)
(e) 21 15

16. (a) 2 (b) 1234 (c) 0.0013075 (d) 34 (e) 30 (f) 400 Class Exercise 1.5
What is the number of significant figures of the following quantities?
(a) 2
(b)
(c)
(d) 34
(e) 30
(f) 400

17. (a) 2 (1) (b) 1234 (4) (c) 0.0013075 (5) (d) 34 (2) (e) 30 (2) or (1)
Class Exercise 1.5
What is the number of significant figures of the following quantities?
(a) (1)
(b) (4)
(c) (5)
(d) (2)
(e) (2) or (1)
(f) (3) or (2) or (1) 17

18. Class Exercise 1.6
Write the following numbers in 3 significant figures.
(a)
(b)
(c)
(d) 18

19. Class Exercise 1.6
Write the following numbers in 3 significant figures.
(a)
(b)
(c)
(d)

20. Remember to bring a CALCULATOR (計算機) and a RULER (直尺) with you in the next lesson.20