The Eye Near and Far Points
The near point is the closest distance for which the lens can
accommodate to focus light on the retina.
Typically at age 10, this is about 18 cm
The average value is about 25 cm.
It increases with age.
Up to 500 cm or greater
Invention of the first Transistor in Nov.17-Dec.23 1947,
the most important invention of the 20th century
Goals
Some knowledge of physics
Critical thinking, idealization, approximation,
mathematical and graphical representations of
phenomena.
Physics 23
Electric Field Introduction
The
electric force is a field force
Field forces can act through space
The effect is produced even with no physical
contact between objects
Faraday
developed the concept of a field in
terms of electric fields
Electric Field
Chapter 24
Gausss Law
Lets return to the field lines and
consider the flux through a surface.
The
number of lines per unit area is
proportional to the magnitude of the electric
field.
Remember this
question about the
strength of the electric
field at the
Applying Gausss Law
To
use Gausss law, you want to choose a
gaussian surface over which the surface
integral can be simplified and the electric field
determined
Take advantage of symmetry
Remember, the gaussian surface is a surface
you choose, it does
Chapter 23
Electric Fields
Todays Class
We will cover properties of electric charge
(23.1)
We will also cover Charging Objects by
Induction (23.2)
We will discuss the difference between a
conductor, semi-conductor, and an insulator.
Finally we will discus
Principal Investigator- Lenny Harrison
Researcher- Jesse Vaught
Data Analyst John Cano
Lab #5: Springs
Researcher by: Jesse Vaught
Part 1:
In order to achieve our desired results, our group first setup an experiment to
measure the k constants of each spri
Principal Investigator- Lenny Harrison
Researcher- Jesse Vaught
Data Analyst Jonathan Cano
Lab #2: Acceleration due to Friction
Analysis- Jonathan Cano
Figure 1- Our measurements
Figure 2- Fast and slow car
In figure 1 you can see the measurements we got
PHY241-009 Group 8
Principal Investigator-Jonathan Cano
Researcher-Lenny Harrison
Data Analyst-Jesse Vaught
Lab #3: Acceleration on an Inclined Track
Principal Investigator-Jonathan Cano
Lab 3 consists of measuring the acceleration of a car on an inclined
Pre Lab 5
Jesse Vaught
Physics Lab 1 Section 009
Group 8
1. m1g = -k(L1-L0)
2.
3. Judging by the graph it takes the object 10 seconds to complete a full bounce,
therefore the period of the wave or bounce is 10 seconds.
4. The frictional force due to stati
PHY241-009 Group 8
Principal Investigator-Lenny Harrison
Researcher-Jesse Vaught
Data Analyst-John Cano
Lab #2: Acceleration due to Friction
Principal Investigation by: Lenny Harrison
Lab 2 consists of measuring the acceleration of a car o
Pre Lab #3
Incline Track
Jesse Vaught- Group 8
1. Read lab 3
2. To calculate the angle opposite of the height, you simply take the sin function
of height over the hypotenuse l. Angle theta is equal to the sin of (h/l).
3. A) The maximum poss
Principal Investigator- Lenny Harrison
Researcher- John Cano
Data Analyst- Jesse Vaught
Lab 3: Acceleration on an Incline Track
Data Analysis by: Jesse Vaught
Figure 1- The data above represents the height, length, and angle
measurements we obtained from
Pre Lab #3
Incline Track
Jesse Vaught- Group 8
1. Read lab 3
2. To calculate the angle opposite of the height, you simply take the sin function
of height over the hypotenuse l. Angle theta is equal to the sin of (h/l).
3. A) The maximum possible value of
PHY241-009 Group 8
Principal Investigator-Lenny Harrison
Researcher-Jesse Vaught
Data Analyst-John Cano
Lab #2: Acceleration due to Friction
Principal Investigation by: Lenny Harrison
Lab 2 consists of measuring the acceleration of a car on a flat track m
PHY241-009 Group 8
Principal Investigator-Jonathan Cano
Researcher-Lenny Harrison
Data Analyst-Jesse Vaught
Lab #3: Acceleration on an Inclined Track
Principal Investigator-Jonathan Cano
Lab 3 consists of measuring the acceleration of a car on an inclined
General Univ: Physics ll.
Blue Test One (odd sections).
Name:
Signature:
ID No:
Section No:
Answer all problems and questions. On problems show all working
out. You have fty minutes.
1 + true/false 18 / 25 points
Problem 9 / 25 points
Problem 10 /25 point
Electrostatic Equilibrium
When
there is no net motion of charge
within a conductor, the conductor is said to
be in electrostatic equilibrium
Properties of a Conductor in
Electrostatic Equilibrium
The electric field is zero everywhere inside the
conductor
Conductors in Electric Field
Why?
Inaconductorelectronsarefreetomove.IfaconductorisplacedintoE,a
forceF=eEactsoneachfreeelectron.Soonelectronswillpileuponthe
surfaceononesideoftheconductor,whilethesurfaceontheothersidewill
bedepletedofelectronsandhaveanet
Summary
Electric potential: PE per unit charge, V= PE/q
Potential difference: work done to move the charge
from one point to another,
Vab=Vb-Va= PE/q=-Wab/q or Wab=-qVab
For uniform electric field: Vab=-Ed
For electric potential due to a point charge:
V=k
Chapter 27Electric Currents
Electric Current
Ohms Law
Resistivity
Electric Power
Superconductivity
Electric Current
If the net charge Q goes past in the time
interval t, then the average current is
I=Q/t
(Electric Current)
The unit of electric current is
F =qv B
Force on a Charged Particle in a
Magnetic Field
Consider a particle
moving in an external
magnetic field so that its
velocity is perpendicular
to the field.
The force is always
directed toward the
center of the circular
path.
The magnetic force
ca
Faradays Law of Induction Statements
The emf induced in a circuit is directly proportional to
the time rate of change of the magnetic flux through the
circuit.
d B
=
Mathematically,
dt
Remember B is the magnetic flux through the circuit
and is found by B
Chapter 36
Image Formation
Image of Formation
Images can result when light rays encounter flat or curved surfaces between two
media.
Images can be formed either by reflection or refraction due to these surfaces.
Mirrors and lenses can be designed to form
Chapter 33
Alternating Current Circuits
Alternating Current Circuits
Electrical appliances in the house use alternating current (AC) circuits.
If an AC source applies an alternating voltage to a series circuit containing
resistor, inductor, and capacitor,
Chapter 34
Electromagnetic Waves
Electromagnetic Waves
Mechanical waves require the presence of a medium.
Electromagnetic waves can propagate through empty space.
Maxwells equations form the theoretical basis of all electromagnetic waves
that propagate
Chapter 35
The Nature of Light and the Laws of Geometric Optics
Introduction to Light
Light is basic to almost all life on Earth.
Light is a form of electromagnetic radiation.
Light represents energy transfer from the source to the observer.
Many phenomen
Summary
Chapters 29-32
Chapter 29
Magnetic field is defined in terms of
the force on a moving charge
B=F/qvsin for a moving charge
or F=qv x B
B=F/Ilsin
or F=lI x B
for a current
Chapter 30
Magnetic Field for a Long, Straight
If the conductor is anSpecial