Introduction to general physics, scientific notation and significant figures

1. GENERAL
SCIENCE
I

3. WHAT WE WILL LEARN
!!!The use of scientific notation and the appropriate,
number of significant figures is important in Physics.
We will become familiar with the international unit system
and the definition of the base units as well as methods of
converting among other unit systems.
We will use available length, mass, and time scales to
establish reference points for grasping the vast diversity
of systems in physics.We will apply a problem-solving strategy that will be useful in
analyzing and understanding problems throughout this
course and in science and engineering applications.

4. WHY STUDY PHYSICS?
Physics is the science on which all other natural and engineering
sciences are built.
The study of physics will help you grasp the scales of
measurements.
Physics is intimately connected with mathematics.
Physics helps remove irrationality from our explanations of the
world around us.
Physics helped us obtain a deeper understanding of our
surroundings.

5. SCIENTIFIC
NOTATIONIt represents a number as the product
of a number greater than or equal to
1 and less than 10 (called the
mantissa) and a power (or exponent)
of 10.
number = mantissa *

6. SCIENTIFIC
NOTATION
number = mantissa *
10exponent7, 000, 000, 000, 000, 000, 000, 000,
000, 000
(7*1027)

7. SCIENTIFIC
NOTATIONHow many atoms are contained in the bodies of all the
people in the Earth? Earth hosts approximately 7 billion
humans.
(7*1027) – number of atoms in
the body(7*109) – number of people on
Earth(7*1027)*(7*109) = 49*1036 =
37

8. SCIENTIFIC FIGURES
It is the number of digits
in the mantissa.

9. SCIENTIFIC FIGURES
The number of significant figures is the
number of reliably known digits.
1.62 has three
s.f1.6 has two s.f
1.6254 has five

10. SCIENTIFIC FIGURES
If you give a number as an integer, you
specify it with infinite precision.
3 children
5 students
3,891 apples

11. SCIENTIFIC FIGURES
Leading zeros do not count as significant
digits.
1.62 has three
s.f0.00162 has three
s.f0.0498 has three s.f

12. SCIENTIFIC FIGURES
Trailing zeros, on the other hand, do count
as significant digits.
1.620 has four
s.f0.001620 has four
s.f0.049800 has five s.f

13. SCIENTIFIC FIGURES
Numbers in scientific notation have as many
as significant figures as their mantissa.
1.6 x 1027 has
two s.f
4.312 x 10-45 has
four s.f4.9 x 10-1000 has two

14. SCIENTIFIC FIGURES
Multiplication and Division
1.23 / 3.4461 is not equal to
0.3569252
1.23 / 3.4461 =
0.357

15. SCIENTIFIC FIGURES
Addition and Subtraction
1.23 + 3.4461 is not equal to
4.6761
1.23 + 3.4461 =
4.68

16. SCIENTIFIC
NOTATIONHow many atoms are contained in the bodies of all the
people in the Earth? Earth hosts approximately 7 billion
humans.
(7*1027) – number of atoms in the
body(7*109) – number of people on
Earth
(7*1027)*(7*109) = 49*1036 =
4.9*1037
4.9*1037 =

17. LET’S TRY IT !!!
1.
2.
3.
How many significant figures are in each of the
following numbers?
2 150
0.000251
215.00
0.215000
0.25 -
0.2170.251 x
0.21
4.
5.
6.

18. LET’S TRY IT !!!
a.
b.
c.
For the two numbers x=0.43 and y=3.53, which
of the following has the greatest number of
significant figures?
the sum,
x+ythe product,
xy
the difference,
x-y
the
number xthe
number y
d.
e.

19. SI UNIT SYSTEM
It is the standard used for scientific work around
the world.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

20. SI UNIT SYSTEM
1 meter is the distance that a light beam in
vacuum travels in 1/299,792,458 of a second. The
meter was related to the size of the Earth.
1 kilogram is defined as the mass of the
international prototype of the kilogram.
1 second is the time interval during which 9, 192,
631, 770 oscillations of the electromagnetic wave
that corresponds to the transition between two
specific states of the cesium-133 atom.

21. SI UNIT SYSTEM
DERIVED UNIT NAME SYMBOL EQUIVALENT EXPRESSIONS
Absorbed dose gray Gy J/kg m2s-2
Angle radian rad - -
Capacitance farad F C/V m-2kg-1s4A2
Catalytic activity katal kat - s-1mol
Does equivalent sievert Sv J/kg m2s-2
Electric charge coulomb C - s*A
Electric
conductance
siemens s A/V m-2kg-1s3A2

22. SI UNIT SYSTEM
DERIVED UNIT NAME SYMBOL EQUIVALENT EXPRESSIONS
Electric
potential
volt V W/A M2kg*s-3A-1
Electric
resistance
ohm Ω V/A M2kg*s-3A-2
Energy joule J
Force
Frequency
Illuminate
Inductance

23. SI UNIT SYSTEM
DERIVED UNIT NAME SYMBOL EQUIVALENT EXPRESSIONS
Luminous
flux
Magnetic flux
Magnetic field
Power
Pressure
Radioactivity
Solid angle

24. SI UNIT SYSTEM
DERIVED UNIT NAME SYMBOL EQUIVALENT EXPRESSIONS
Absorbed
dose
Angle
Capacitance

25. SI UNIT SYSTEM
DERIVED UNIT NAME SYMBOL EQUIVALENT EXPRESSIONS
Absorbed
dose
Angle
Capacitance