1. Mechanics of point particles why study physics ?
Physics is the science on which all other natural and engineering sciences are built.
All modern technological advances back directly to basic physics.
A good grasp of essential physics concepts gives you a solid foundation on to construct advanced knowledge in all sciences .
Physics is intimately connected with mathematics , because it brings to life the abstract concepts used in trigonometry, algebra, and calculus.

2. Mechanics of point particles why study physics ?
5. Science, especially physics, helps remove irrationality from our explanation of the world around us .
6. Physics has helped us to obtain a deeper understanding of our surrounding snd has given us greater ability to control them
7. Physics drives much of the technology essential to progress in chemistry and the life science .
8. Thus we need to acquire scientific literacy an essential tool for every citizen in our technology-driven society.
9. A billion is equal to a thousand millions (1,000 x 1,000,000).

3. Mechanics of point particles Working With Numbers
A measurement is the combination of a number and a unit .
How to deal with very big or very small numbers .
Scientific notation
Number = mantissa x 10 exponents
To multiply two numbers in scientific notation, we multiply their mantissas and then add their exponents .
To divide two numbers in scientific notation ( A / B ) we divide the mantissa of A by mantissa of B and then subtract the exponent of B from exponent of A.

4. Mechanics of point particles Working With Numbers
Choose the correct answer to the following questions ( page 27 )
1.1 Which of the following is the frequency of the musical note C5.
A ) 376 g b) 438 m/s C ) 523 Hz d) 265 J

5. Mechanics of point particles Working With Numbers
Rules of Significant figures :
The number of significant figurers is the number of reliably known digits . For example : 2.34 has significant figures , while 1.3 has significant figurer .
If you give a number as an integer, you specify it with infinite precise . For example you have 5 finger in your hand.
Leading zero do not count as significant digits.
Trailing zero, on the other hand, do count as significant digits. For instance, the number has significant figures .
Numbers in significant notation have as many significant figures as their mantissa. for example, the number 3.33 x has significant figures , because that is what the mantissa ( ) has . The size of exponent has no influence .
You can never have more significant figures in result than you start with in any of factors of a multiplication or division . For example : x 2.5 = x 6.2 = x 10 =
Role for adding and subtracting: We should see to the decimals for both numbers, then the result should have the least numbers of decimals, for instance:
a ) = b) = c ( =

6. Unit Abbreviation Base Unit for
Unit Names and Abbreviations for the Base Units of the SI System of Units
Unit
Abbreviation
Base Unit for
Meter m
Length
Kilogram Kg
Mass
Second S
Time
Ampere A
Current
Kelvin K
Temperature
Mole
mol
Amount of a substance
candela cd
Luminous intensity

8. 1. 3 Compare three SI units millimeter, kilogram, and microsecond
1.3 Compare three SI units millimeter, kilogram, and microsecond. which is the largest ?
a)Millimeter c) microsecond
b)Kilogram d) the units are not comparable