1. Lectures for the 1st year Electronics and Telecommunications
PHYSICS
Einstein
Newton
Lectures for the 1st year
Electronics and Telecommunications

2. Resources Professor : Tadeusz Pisarkiewicz (lecturer)
Office in C1 building, Room 316,
(login: ESA, password: ESA)
Teaching Assistant: (classes)
dr Konstanty Marszałek,
Textbook: Fundamentals of Physics, parts 1 - 5,
D. Halliday, R. Resnick, J. Walker, Wiley & Sons, Inc.

3. What is “Physics” prof. Tom Murphy – UCSD:
An attempt to rationalize the observed Universe in terms of irreducible basic constituents, interacting via basic forces.
Reductionism!
An evolving set of (sometimes contradictory!) organizing principles, theories, that are subjected to experimental tests.
This has been going on for a long time.... with considerable success

4. Reductionism Kepler’s laws of Falling apples planetary motion
Attempt to find unifying principles and properties e.g., gravitation:
Kepler’s laws of
planetary motion
Falling apples
Universal
Gravitation
“Unification” of forces

5. Reductionism, cont. All the stuff you see around you
Chemical compounds
Elements (Atoms)
e,n,p
Many thousands
Many hundreds
Tens 3
An ongoing attempt to deduce the basic building blocks
Superstrings?

6. Fundamental interactions
gravitational interactions
example: the force that holds the Moon in its orbit and makes an apple fall.
Newton’s law of gravitation
F - force of interaction between particles with masses m1 and m2 ,
r – the distance between particles,
G = 6.67 x Nm2/kg2 , the gravitational constant.
electromagnetic (EM) interactions
Basic interactions in everyday life (EM radiation, cohesion, friction,
chemical and biological processes, etc.) between electric charges and
magnetic moments
Coulomb’s law
Q1, Q2 – point electric charges separated by distance r
εo – permittivity constant, F – static el. force (attractive or repulsive)

7. Fundamental interactions, cont.
strong interactions
Responsible for binding of nucleons to form nucleus (nuclei)
and for nuclear reactions.
Short-range interactions (~10-15m).
Simple laws of interaction do not exist.
weak interactions
Responsible for β decay and for disintegration of many elementary particles.
Short-range interactions (~10-15m), which do not give bound objects.
Comparison of interaction intensities
Interaction Relative intensity
strong 1
EM x 10-3
weak
gravit x 10-39

8. Vector calculus
There are quantities that can be completely described by a number and are known as scalars. Examples: temperature, mass.
Other physical parameters require additional information about direction and are known as vectors. Examples: displacement, velocity, force.
magnitude
direction
sense
All vectors in Fig.(a) have the same magnitude and direction.
A vector can be shifted without changing its value if its length
and direction are not changed.
All three paths in (b) correspond to the same
displacement vector.
Vectors are written in two ways: either by using an arrow above or using boldface print.

9. Vector components
Each vector can be resolved into components, e.g. by projection on the axes of a rectangular coordinate system
The scalar component is obtained by drawing perpendicularly straight lines from the tail and tip of the vector to the x axis.
By using unit vectors (vectors having magnitude
of exactly 1 and pointing in a particular direction)
one can express vector as

10. Addition of vectors
Vectors can be added geometrically or in a component form (using algebraic rules).
Geometric addition
The tail of is placed at the tip of .
The resultant vector connects the tail of and the tip of (polygon method).
Vector sum is the diagonal connecting common
vectors origin with the opposite corner of a parallelogram (parallelogram method).
Algebraic addition

11. Vector subtraction
Vectors can be also subtracted geometrically or by components.
The subtraction can be reduced to vector addition (with changed sense).
Parallelogram method
Polygon method
Algebraic subtraction

12. The scalar product
The scalar product (dot product) of two vectors gives scalar and is defined as follows:
(orthogonality criterion: )
The dot product can be considered as the product of the magnitude of one vector and the scalar component of the second vector along the direction of the first vector.
Using component notation one obtains for the dot product in three dimensions:

13. The vector product The vector product (cross product) of two vectors
is a vector, whose magnitude is
The direction of vector is perpendicular to the plane defined by multiplied vectors and its sense is given by the right-hand rule.

14. The vector product, cont.
In terms of vector components one calculates the
determinant:
The order of two vectors in the cross (vector) product is important: