Physics 1A
Introduction to Mechanics (Motion, Force, Energy)
Prof. Doug Smith
Course website (lots of info):
http:/sites.google.com/site/smithcourse
Write this down, check for updates
Relevance of physics?
Walk into a doctors office
Relevance of physics?
Chapter 5: More Applications of Newtons Laws
5.1 Sliding friction
5.1: Forces of Friction (sliding)
 In Ch. 14 we neglected sliding friction
5.2: Uniform circular motion (centripetal force)
 When a real object is pushed across a real surface, there is
Brief Summary for Physics 1a Final
Note: These are short summaries, not intended as a substitute for the full explanations in lectures and the book.
A vector can be written as = + , where and are the x and y components (math)
Magnitude of , called "A" c
Formula sheet Physics 1a Final  Note: You have to understand how to use these formulas and why they are
true. Reading this sheet is not a substitute for reading the book and listening to lectures.
Vector notation: = + , 2 = 2 + 2 , = cos(), = sin()
= (
Chapter 8: Momentum and Collisions
8.1 8.2 Conservation of momentum
8.1: Linear Momentum and Its Conservation
 Consider two ice skaters who start at rest and then push
apart from each other, and thereby move in opposite
directions
8.2: Impulse and Momen
Chapter 3: Motion in Two Dimensions
3.1: Position, Velocity, and Acceleration Vectors
3.2: 2D motion with Constant Acceleration
3.3: Projectile Motion
3.4: Uniform Circular Motion
3.5: Tangential and Radial Acceleration
Vectors are needed to describe two
Equations for rotational motion
Chapter 10 Rotational Motion
Our last chapter hooray!

Mathematically two equations are analogous if they have
the same form but use different variable names

The variables and equations for rotational motion are
analogou
Physics 1A
Lecture 5B!
!
"Education is the ability to listen to almost anything
without losing your temper or your selfconfidence."
Robert Frost
Learning Goals
Describe what conditions need to be met for
static equilibrium to occur.!
Calculate the magni
Physics 1A
Lecture 4D
"Success requires first expending ten units
of effort to produce one unit of results.
Your momentum will then produce ten
units of results with each unit of effort.
Charles Givens
Learning Goals
Differentiate between elastic collisi
Physics 1A
Lecture 5A
"The lazy manage to keep up with the earths
rotation just as well as the industrious.
Mason Cooley
Quiz #4 Info
It will be a Scantron test covering
forces and motion (WS 4A through 4D).
A list of equations, constants, and
conversion
Physics 1A
Lecture 4C!
"Standardization is the surest way to destroy
the initiative, to benumb the creative
impulse above all else essential to the
vitality and growth of democratic ideals.
Ida Tarbell
Learning Goals
Describe the differences between impu
Physics 1A
Lecture 4B!
"Every time you don't follow your inner
guidance, you feel a loss of energy, loss of
power, a sense of spiritual deadness.
Shakti Gawain
Quiz 3
55.5% average is normal (scores of 5 and above
are ne when considering MetaCog/Notecard
Physics 1A
Lecture 4A
"Be master of your petty annoyances and conserve
your energies for the big, worthwhile things. It isn't
the mountain ahead that wears you outit.s the
grain of sand in your shoe.
Robert Service
Learning Goals
Differentiate between w
Physics 1A
Lecture 3E
"Whenever you find yourself on the side of
the majority it's time to pause and reflect."
Mark Twain
Quiz #3 Info
It will be a Scantron test covering
forces and motion (WS 3A through 3E).
A list of equations, constants, and
conversio
Physics 1A
Lecture 3C
"Example is not the main thing in influencing
others. It is the only thing."
Albert Schweitzer
Learning Goals
Determine the relative accelerations and Third
Law pairs for attached masses.
Use force diagrams to nd motion variables (x
Physics 1A
Lecture 3D!
"I have not failed. I've just found 10,000
ways that won't work."
Thomas Edison
Learning Goals
Determine how forces and force diagrams can
help you to nd out if energy is being
transferred into or out of a system.!
Identify how a s
Physics 1A
Lecture 3B!
"That which has always been accepted by everyone,
everywhere, is almost certain to be false."
Paul Valery
Quiz 2
61.8% average is normal (scores of 5 and above
are ne when considering MetaCog/Notecards).!
Question 2: Static Equilib
Physics 1A
Lecture 3A
"Adversity is the first path to truth."
Lord Byron
Learning Goals
Determine the differences between static
friction and kinetic friction, including when a
physical situation calls for one instead of the
other.
Use static friction in
Tuesday, September 29, 2015
Module 2!
Physical quantities
 all have magnitude (# reporting physical quant) and unit both have to be in place!
c= 8.0 x 10 ^ 8 m/s!
 can include direction!
F= 20.0 N down!
 SCIENTIFIC NOTATION!
height of person 2.0 me
Tuesday, September 29, 2015
Module 1!
Subject
 What we may think of an apple is not what others may think of an apple small but
what if given to a baby?= we must quantify= Physical quantities are the properties of
a physical object that can be measured
Wednesday, September 30, 2015
Kinematic Quantities!
Kinematics Quantities
quantities describing a motion of object !
Includes position, displacement, velocity and acceleration!
important bc need to be specic like when asking for directions!
increasing
Wednesday, September 30, 2015
Transforming Between Position, Displacement,
Velocity and Acceleration!
!
 Denitions: !
Positions location relative to origin!
Displacement difference between two positions independent of coordinate system!
Velocity d
Wednesday, September 30, 2015
Position, Velocity and Acceleration Diagrams!
Subject
 PVA diagrams are graphical tools for analyzing 1d motions visualize and make
predictions how motion initiated !
Infer initial conditions when time=0!
Determine 1st de
Notes: Notes:
1. Turbulence is a very difficult phenomenon to analyze. It is typically studied using semiempirical analyses, i.e.
those analyses that use both theory and experimental data. The transition region is even more difficult to
analyze.
2.
The u
The vorticity transport equation is an alternate expression of the NavierStokes equations. Consider the
NavierStokes equations for an incompressible fluid with constant dynamic viscosity:
Du
= p + 2 u + f
Dt
Divide through by the density, , (note that i
Example:
1.
5
Using the Moody chart, determine the friction factor for a Reynolds number of 10 and a relative
roughness of 0.001.
2.
What is the friction factor for a Reynolds number of 1000?
3.
What is the friction factor for a Reynolds number of 10 in a
u
=0
t
Taking the dot product of Eqn. (4.131) with a little length of line, dx, that is along either a streamline or
a vortex line gives:
dp
+ 1 2 u u + G dx = ( u ) dx
(4.132)
Since the vector (u) is perpendicular to both the streamline and the vortex l