PHY101 Complete Handouts

TABLE OF CONTENTS

I.

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LECTURE SUMMARIES

Page # Lecture 1 Introduction to physics and this course Lecture 2 Kinematics – I Lecture 3 Kinematics – II Lecture 4 Force and Newton’s Laws Lecture 5 Applications of Newton’s Laws – I Lecture 6 Applications of Newton’s Laws – II Lecture 7 Work and Energy Lecture 8 Conservation of Energy Lecture 9 Momentum Lecture 10 Collisions Lecture 11 Rotational Kinematics Lecture 12 Physics of Many Particles Lecture 13 Angular Momentum Lecture 14 Equilibrium of Rigid Bodies Lecture 15 Oscillations – I Lecture 16 Oscillations – II Lecture 17 Physics of Materials Lecture 18 Physics of Fluids Lecture 19 Physics of Sound Lecture 20 Wave Motion Lecture 21 Gravitation Lecture 22 Electrostatics – I Lecture 23 Electrostatics – II Lecture 24 Electric Potential Lecture 25 Capacitors and Currents Lecture 26 Currents and Circuits Lecture 27 The Magnetic Field Lecture 28 Electromagnetic Induction Lecture 29 Alternating Current Lecture 30 Electromagnetic Waves Lecture 31 Physics of Light Lecture 32 Interaction of Light with Matter Lecture 33 Interference and Diffraction Lecture 34 The Particle Nature of Light Lecture 35 Geometrical Optics Lecture 36 Heat – I Lecture 37 Heat – II Lecture 38 Heat – III Lecture 39 Special Relativity – I Lecture 40 Special Relativity – II Lecture 41 Matter as Waves Lecture 42 Quantum Mechanics Lecture 43 Introduction to Atomic Physics Lecture 44 Introduction to Nuclear Physics Lecture 45 Physics of the Sun Purpose: This course aims at providing the student a good understanding of physics at the elementary level. Physics is essential for understanding the modern world, and is a definite part of its culture.

Background: It will be assumed that the student has taken physics and mathematics at the F.Sc level, i.e. the 12th year of schooling. However, B.Sc students are also likely to find the course useful. Calculus is not assumed and some essential concepts will be developed as the course progresses. Algebra and trigonometry are essential. However, for physics, the more mathematics one knows the better.

Scope and Duration: The course has 45 lectures, each of somewhat less than one hour duration. All main fields of physics will be covered, together with several applications in each.

Language: For ease of communication, all lectures are in Urdu. However, English or Latin technical terms have been used where necessary. The student must remember that further study and research in science is possible only if he or she has an adequate grasp of English.

Textbook: There is no prescribed textbook. However, you are strongly recommended to read a book at the level of “College Physics” by Halliday and Resnick (any edition). There are many other such books too, such as “University Physics” by Young and Freedman. Study

any book that you are comfortable with, preferably by a well-established foreign author. Avoid local authors because they usually copy. After listening to a lecture, go read the relevant chapter. Please remember that these notes cover only some things that you should know and are not meant to be complete.

Assignments: There will be total Eight Assignment in this course and its schedules will be announced from time to time. The book you choose to consult will have many more. Those students who are seriously interested in the subject are advised to work out several of the questions posed there. In physics you cannot hope to gain mastery of the subject without extensive problem solving.

Examinations: Their schedules will be announced from time to time.

Tutors: Their duty is to help you, and they will respond to all genuine questions. However, please do not overload them as they have to deal with a large number of students. Happy studying!

Acknowledgements: I thank the Virtual University team and administration for excellent cooperation, as well as Mansoor Noori and Naeem Shahid, for valuable help.

Summary of Lecture 1 – INTRODUCTION TO PHYSICS

1. Physics is a science. Science works according to the scientific method. The scientific method accepts only reason, logic, and experimental evidence to tell between what is scientifically correct and what is not. Scientists do not simply believe – they test, and keep testing until satisfied. Just because some “big scientist” says something is right, that

thing does not become a fact of science. Unless a discovery is repeatedly established in different laboratories at different times by different people, or the same theoretical result is derived by clear use of established rules, we do not accept it as a scientific discovery. The real strength of science lies in the fact that it continually keeps challenging itself.

2. It is thought that the laws of physics do not change from place to place. This is why experiments carried out in different countries by different scientists – of any religion or race – have always led to the same results if the experiments have been done honestly and

correctly. We also think that the laws of physics today are the same as they were in the past. Evidence, contained in the light that left distant stars billions of years ago, strongly indicates that the laws operating at that time were no different than those today. The spectra of different elements then and now are impossible to tell apart, even though physicists have looked very carefully.

Q3. This course will cover the following broad categories:

1. Classical Mechanics, which deals with the motion of bodies under the action of forces. This is often called Newtonian mechanics as well.
2. Electromagnetism, whose objective is to study how charges behave under the influence of electric and magnetic fields as well as understand how charges can create these fields.
3. Thermal Physics, in which one studies the nature of heat and the changes that the addition of heat brings about in matter.
4. Quantum Mechanics, which primarily deals with the physics of small objects such as atoms, nuclei, quarks, etc. However, Quantum Mechanics will be treated only briefly for lack of time.
5. Every physical quantity can be expressed in terms of three fundamental dimensions: Mass (M), Length (L), Time (T). Some examples:

Speed Acceleration Force Energy Pressure LT 1 LT 2 MLT 2

You cannot add quantities that have different dimensions. So force can be added to force, but force can never be added to energy, etc. A formula is definitely wrong if the dimensions on the left and right sides of the equal sign are different. ML2T 2 ML1T 2 Scientific method is a step-by-step process.. using observation, experimentation and analysis.