Physics 1A
Lecture 4B
Review of Last Lecture
Last time: Newtons first two simple laws
objects move with constant velocity (magnitude
and direction) unless acted upon by a force
acceleration of object is proportional to force
applied divided by mass
Ma
Physics 1A
Lecture 8D
Review of Last Lecture
An inelastic collision loses kinetic energy
An elastic collision conserves kinetic energy
If two objects stick, we call that a perfectly inelastic
collision
Today
2-D collisions
Many collisions
Rockets
2D
Physics 1A
Lecture 5A
Outline
Last time - Forces always come in action-reaction pairs
The direction of acceleration is always parallel to the net force
The six steps for solving Force problems
Normal forces always point perpendicular to surface
Gravitati
Physics 1A
Lecture 10B
Review of Last Lecture
Rotational motion is independent of translational motion
A free object rotates around its center of mass
Objects can rotate around different axes
Natural unit for angle is the radian which has dimensions of
no
Physics 1A
Lecture 4A
Review of Last Lecture
Uniform circular motion is an accelerated motion
due to change in velocity vector direction (even for
constant speed)
Radial component of the acceleration arises from
the change in direction of the velocity
Physics 1A
Lecture 2B
Outline
Last time
v = dx/dt
a = dv/dt
Velocity = slope of a line in a position versus time plot
Acceleration = slope of a line in a velocity versus time plot
position->velocity->acceleration related by differentiation
acceleration-
Physics 1A
Lecture 8C
Review of Last Lecture
Momentum is always conserved in the absence of net
external force (Newtons Laws)
Energy is conserved in a closed system with no transfer
of energy to the environment
Today
Momentum transfer in inelastic and
Physics 1A
Lecture 10D
Review of Last Lecture
Torque and angular acceleration
Leverage & Balance
Rotational kinetic energy
Moment of Inertia
Today
Moment of inertia
Angular momentum and angular kinetic energy
Equilibrium
Conservation of angular momentum
C
Physics 1A
Lecture 3A
Outline
Last time
Velocity and accelerations
This time Choice of coordinate systems
2D motion (ballistic, time of flight)
Use results from one direction to use in second
direction
Its helpful to choose the right
coordinate syst
Physics 1A
Lecture 3B
Outline
Last time
motion along different axes act independently
Prodigious choice of coordinate system
Time of flight, range
This time Circular motion and centripetal acceleration
Relative velocities
Intersecting trajectories
Physics 1A
REVIEW
"All good things must come to an end.
-Proverb
Choose your weapon
Kinematics
Dynamics
Work, Energy, Collisions
Looking back: Describing motion
Motion Diagrams
General Principles
Displacement, velocity, acceleration are vectors
Velocity
A
Physics 1A
Lecture 10C
Review of Last Lecture
Direction of angular velocity is determined by the right-hand
rule
For cross product
, the direction of C is
determined by the right-hand rule
The equivalent of force in rotational motion is torque
The mag
Physics 1A
Lecture 6B
Review of Last Lecture
Solution to spring force motion is given by the
sine or cosine function
Rate of back-and-forth harmonic motion
quantified by frequency/period
Today systems, environment, concept of
energy and work
Today
Sys
Physics 1A
Lecture 1A
Information
TODAY
Overview
Units
Dimensional analysis
Motion diagrams
Physics: Discipline that attempts to explain a
wide range of natural phenomena with few
underlying principles or laws
Examples:
Same laws that explains how apple
Physics 1A
Lecture 7B
Review of Last Lecture
Total mechanical energy = kinetic + potential energies
A closed system no exchange (mechanical) energy with its
environment
Total mechanical energy is conserved in a closed system
Dissipative forces remove
Physics 1A
Lecture 5C
Review of Friction
Friction Force
Friction force always points parallel to surface
At rest, the friction force is equal and opposite the
applied force
When an object is in motion the magnitude of the
friction force is proportional
Physics 1A
Lecture 8A
Review of Last Lecture
A closed system - no exchange of energy with its
environment mechanical energy is conserved
Dissipative forces Efinal = Einitial Wnc Etransfer
Today
Quiz 3
Power
Momentum
Impulse
Meta assignment Self Assessme
Physics 1A
Lecture 10A
Review of Last Lecture
2D elastic collisions require additional information
Many collisions lead to gradual increase in speed to that
of the colliding particles
Center of Mass position to which forces apply
Todays lecture
Defini
Physics 1A
Introduction
"You do not really understand something unless you
can explain it to your grandmother."
-Albert Einstein
Introduction
Welcome to Physics 1A!
Physics 1 is a three quarter course
designed as an introduction into basic
physics for stu
Physics 1A
Lecture 5B
Review of Last Lecture
Normal force always points perpendicular to surface
Friction force always points parallel to surface
Tension always points along string
Break problem into equations of motion for x and y
directions
Back to Fric
Physics 1A
Lecture 7A
Review of Last Lecture
Energy measures motion or potential for motion
Many processes in nature can be described as an exchange of
different forms of energy
Change in kinetic energy is done by work (WorkKinetic Energy
Theorem)
The
WebAssign Problem Practice
Open a past-due assignment.
The symbol that shows two pieces of
paper with arrows in a circle (kind of like
a recycle symbol) means that a
particular assignment will have this
option
WebAssign Problem Practice
Click on the quest
Physics 1A
Forces
Work
Potential energy
Energy conversion
Lecture 8B
Review of Last Lecture
Newtons original 2nd law stated:
Impulse is change in momentum caused by force acting
over time:
Today
Collisions
Conservation of momentum
Quiz 4 to Monday No
Physics 1A
Lecture 6A
Review of Last Lecture
Spring force always pulls objects toward an
equilibrium position
Strength of spring is quantified by spring
constant
Today
Gravity
Energy
Work
What is gravity?
the inherent attractive force
between objects
Physics 1A
Lecture 1B
Estimation Techniques
In this term you should learn how to estimate basic
physical quantities using simple relations and order
of magnitude numbers (closest factor of 10)
Important for:
Checking solution (does my answer make sense
Physics 1A
Lecture 2A
Outline
Last time
vector - magnitude and direction
Distance is a scalar quantity, displacement is a
vector
This time
Speed and velocity
Speed vs. Velocity
Speed is distance travelled over a given time
period. It is a scalar q
Probability Distributions
Lecture notes for Phys 140A
M.M. Fogler
Random variables
Discrete random variables
Continuous random variables
Outcome of a coin toss / dice
roll
Your total score for Phys 140A
Height of a tree
Coordinate of a molecule in a
g
Entropy and information
Lecture notes for Phys 140A
M.M. Fogler
Outline
Properties of information
Measures of information
Thermodynamic entropy as missing information
Maxwells demon
Szilrds engine
Landauers erasure principle
Some properties of infor