1. PHYS 151 Dr. Richard A Lindgren University of Virginia USA

2. Course Lecture Notes
Textbook: Physics for Scientist and Engineers Fourth Edition
Author Giancoli

3. Physics for Scientists & Engineers, with Modern Physics, 4th edition
Lecture PowerPoints
Chapter 1
Physics for Scientists & Engineers, with Modern Physics, 4th edition
Giancoli

4. Final Grade Determination
Attendance 5%
Homework 25%
Quiz %
Quiz %
Final %

5. Syllabus First Week Tuesday Wednesday Thursday Friday
1. Measurement and Estimating
2. Projectile Motion
Wednesday
3. Kinematic in 2D
Thursday
3. Kinematics in 2D
4. Newtons Laws
Friday

6. Syllabus Second Week Monday Tuesday Wednesday Thursday Friday
5. Friction, Drag forces, and Circular motion
Tuesday
Quiz 1
Wednesday
6. Gravitation
Thursday
7. Work and Energy
Friday
8. Conservation of Energy

7. Syllabus Third Week Monday Tuesday Wednesday Thursday Friday
8. Conservation of energy
Tuesday
Quiz 2
9. Conservation of Momentum
Wednesday
Thursday
10. Rotational Motion
Friday
11. Angular Motion

8. Syllabus Fourth Week Monday Tuesday Wednesday
11. Angular Momentum
Tuesday
12. Static Equilibrium, Elasticity and Fracture
Wednesday
12. Static Equilibrium, Elasticity and Fracture
Review
Thursday
Final Exam
Friday
Grade Determination

9. Assignment 1 Chp 1 1-33,1-52 Chp 2 2-58, 2-72 Chp 3 3-22, 3-80
Due Monday 10:00

10. Chapter 1 The Nature of Science Models, Theories, Laws and Principles
Units, and unit conversions
Measurement, Accuracy, Precision, and significant figures
Dimensional analysis
Estimating and Approximations
Matter and Interactions
Principles – predict the future
Short Math Review
Vectors and Calculus

11. The system of units we will use is the
Standard International (SI) system;
the units of the fundamental quantities are:
Length – meter
Mass – kilogram
Time – second

12. Fundamental Physical Quantities and Their Units
Unit prefixes for powers of 10, used in the SI system:

14. Accuracy and Significant Figures
The number of significant figures represents the accuracy with which a number is known.
Terminal zeroes after a decimal point are significant figures:
2.00 has 3 significant figures
2 has 1 significant figure.
Important for webassign in getting the correct answer
For the homework problems (2%).

15. Accuracy and Significant Figures
If numbers are written in scientific notation, it is clear how many significant figures there are:
6. × 1024 has one
6.1 × 1024 has two
6.14 × 1024 has three
…and so on.
Calculators typically show many more digits than are significant. It is important to know which are accurate and which are meaningless.

16. Scientific Notation Example
Scientific notation: use powers of 10 for numbers that are not between 1 and 10 (or, often, between 0.1 and 100):
When multiplying numbers together, you add the exponents algebraically.
When dividing numbers, you subtract the exponents algebraically.
Example

17. 1-4 Dimensional Analysis
The dimension of a quantity is the particular combination that characterizes it (the brackets indicate that we are talking about dimensions):
[v] = [L]/[T]
Note that we are not specifying units here – velocity could be measured in meters per second, miles per hour, inches per year, or whatever.
Force=ma [F]=[M][L]/[T2]

18. Estimates or Guesstimates– How a Little Reasoning Goes a Long Way
Estimates are very helpful in understanding what the solution to a particular problem might be.
Generally an order of magnitude is enough – is it 10, 100, or 1000?
Final quantity is only as accurate as the least well estimated quantity in it

19. Guesstimates How many golf balls would it take to circle the equator ?
N= Circumference of Earth/ Diameter of Golf Ball
Diameter of the golf ball is about 2 inches or 4 cm.
How to estimate the circumference of the earth?
US is 3000 miles wide because it takes a jet at 500 mph to fly from NY to LA in 6 hours
It is also 3 times zones wide and there are 24 time zones across the world and therefore the circumference is 3000 x 24/3=24,000 miles or 40,000 km

20. Principles or Laws Mathematics Predict the future
Conservation of Energy
Conservation of Momentum
Newton's Laws
Principle of Relativity
Laws of physics work the same for an observer in uniform motion as for an observer at rest.
Mathematics
Predict the future

21. In this course we will mostly work with the following forces
Friction
Gravity
Contact forces
Spring forces
Buoyant forces
……….
Also keep in mind that we assume in many instances when we have contact interactions, we assume also that we are dealing with rigid bodies. In actual fact a body is never purely rigid.

22. Rigid Body is made up of Matter
Matter is made up of atoms which is made up of electrons orbiting the nucleus. This gives us our solids, liquids and gases. For example the surface of a solid might look something like this.

23. Solids STM images of a surface through silicon
Atoms are arranged in a crystalline array or 3D solid
Note defects in the lower image

24. Ordinary matter on earth is made up of tiny Atoms

25. Other Interactions (Action at a distance) Also called fundamental interactions.
Strong - inside the nucleus of the atom
Electromagnetic - between charged particles
Electric
Magnetic
Weak - involves the neutrino
Strength : Strong > electromagnetic >
weak > gravitational

26. Math Review Short Math Review Algebra - Trigonometry and geometry
Solving simultaneous equations
Cramers Rule
Quadratic equation
Trigonometry and geometry
sin, cos, and tan, Pythagorean Theorem,
straight line, circle, parabola, ellipse
Math Review
Vectors
Unit vectors
Adding, subtracting, finding components
Dot product
Cross product
Derivatives
Integrals

27. Arc Length and Radians S
is measured in radians

28. Pythagorean Theorem
EXAMPLE

29. Trigonometry
EXAMPLE

30. Simultaneous Equations
FIND X AND Y

31. Cramer’s Rule

32. Cramer’s Rule

33. Quadratic Formula
EQUATION:
SOLVE FOR X:
SEE EXAMPLE NEXT PAGE

34. Example

35. Derivation
Complete the Square

36. Small Angle Approximation
A useful simplification of the laws of trigonometry
which is approximately true for very small angles.
For
EXAMPLE

37. How would you estimate the radius of the Earth roughly? Chap 1-33