Download Physics - INSTYTUT FIZYKI PWr

Physics I
Prof. dr hab. Ewa Popko
office: room 231a, A-1
www.if.pwr.wroc.pl/~popko
e-mail:
[email protected]
Based on the lectures by prof. J.M.Wróbel, KSU, Missouri
manuals
 D.Halliday, R.Resnick, J.Walker;
Fundamentals of Physics, Extended ( polish ed.
Podstawy Fizyki tom 1 i 2
H.D. Young, R.A. Freedman; University
Physics,
W.I Sawieliew; Wykłady z Fizyki tom I
 K.Jezierski, B.Kołodka, K.Sierański; Wzory i
Prawa z Objaśnieniami, część I
 K.Jezierski, B.Kołodka, K.Sierański; Zadania
z Rozwiązaniami, część I
Physics
- Part of science that describes (not
"explains") the behavior of matter and its
interactions at the most fundamental level.
Physics
is
based
on
experimental
observations.
Geology,
chemistry,
engineering,
astronomy, biology, psychology and medicine
all 'require' an understanding of the principles
of physics.
Matter- materia;
principles – podstawy, zasady
classical physics
a) classical mechanics: the study of motion
b) thermodynamics: the study of energy
transfer
c) electromagnetism: electricity, magnetism,
optics
Motion - ruch
modern physics
a) relativity: a theory of the behavior of
particles at high speeds
b) quantum mechanics: a theory of the
submicroscopic world
Modern – współczesna, quantum mechanics – mechanika
kwantowa
Relativity – względność
quantum mechanics – mechanika kwantowa
Structure of physics
• Physics describes, in an approximate way, the
natural phenomena taking place in the universe.
• An abstract model, using imaginable elements and
mathematical relations is created to analyze the
phenomena.
• Phenomena – zjawiska
• the universe – wszechświat
• Relations -związki
Because of their simplicity and accuracy,
mathematical models are used to represent
nature. The most common mathematical
concepts used for this purpose are:
numbers
vectors
tensors
functions
operators
xx xy xz
55 km/h
yx yy yz
zx zy zz
y(t)
=
A
sin (t)
[5,4,3] N

p̂ x  i
x
120 kJ
Concepts – pojęcia, simplicity – prostota, accuracy - dokładność
Measurement (pomiar)
The procedure, which assigns
a mathematical quantity to a
physical quantity is called a
measurement. A measurement
is based on a comparison of
the given element of the
quantity with a chosen
element called a standard.
Assigns – przypisuje, a quantity – wielkość, a comparison – porównanie.
Units (jednostki)
The most commonly used SI (metric) system
is based on m, kg, s, mole. In some cases it is
convenient to introduce other units by adding
prefixes.
femto- 10-15
pico- 10-12
nano- 10-9
micro- 10-6
mili- 10-3
centi- 10-2
SI – international standard
kilo- 103
mega- 106
giga- 109
Scalars (skalary)
The character of a physical quantity is
determined by the rules of combination of that
quantity.
A scalar quantity obeys the same rules
of combination as numbers. Each scalar
quantity can be represented by a number.
3+2=5
Time
- a scalar quantity associated with changes in the
universe.
(The SI unit is one second defined as a time interval
in which a specific spectral line of cesium-133
(Cs133) performs a defined number of oscillations.)
Oscillations - drgania
Example 1. Time-interval (przedział czasu)
(do not confuse with time-instant - chwila)
A repetitive process is used as a time
counter (a clock). The number of
repetitions is the value assigned to the
time-interval.
Repetitive – powtarzający się,
Distance
- a scalar quantity associated
with the relative arrangements
of two points.
(The SI unit one meter defined as the length
of the path travelled by light in a vacuum
during a time interval of 1/299,792,458 of a
second.)
Vacuum – próżnia
Arrangements - ustawienia
s0
Visible Universe
Galaxy Clusters
Milky Way
100 ly marconi
Nearest Star
Solar System
Earth - Sun
Earth
Tallest Mountain
Human
Protozoa
Cell Nucleus
Molecule
Atom
Nucleus
Proton
Quarks
Planck Length
26
10
10 26
24
10
10 24
21
10
10 21
18
10
10 18
116
6
10
10
10
10
113
3
10
10
111
1
00
10
10
-6
-6
10
10
4
10
10 4
8
10
10 8
-3
-3
10
10
-9
10
10 -9
-1
0
-10
10
10
-1 2
10
10 -12
10
10
-1 5
10
10 -15
-1
8
-18
-35
-35
10
10
THE SCALE OF THE UNIVERSE
10-36 10-32 10-28 10-24 10-20 10-16 10-12 10-8 0.0001 1
size (m)
104
108
1012 1016 1020 1024 1028
Mass
- a scalar quantity assigned to the principal
inertial property of a body, i.e. its
'resistance' to a change in motion.
(The SI unit is one kilogram defined as the mass of the
platinum-iridium cylinder kept at the International Bureau of
Weights and Measures.)
Inertial – bezwładny
Resistance -opór
Length
- a scalar quantity associated
with the size of objects and
figures.
The summation sign, i – the index of summation
l

curve
ds 
lim  si
s i 0 i
The definite integral of differential
s over some curve is equal to the
limit ( as delta si approaches zero)
of the sum of the delta si
Integral - całka
Differential – różniczka
Density (gęstość)
The (differential) mass dm of a
(differential) volume dV of a
substance is proportional to the
volume.
dm    dV
The proportionality coefficient is called the
density of the substance.
Coefficient – współczynnik
Volume - objętość
example: (uniform density)
mass of a differential fragment
dm  0dV
total mass
M
 0dV  0   dV  0V
object
object