Class Notes 1/27/16 - Physics Internal Website

Physics 122 - Lecture
Date: 01/27/16
Questions?
How many exams does the syllabus
say we'll have?
A) 2 during the semestar + mandatory final exam
B) 2 during the semestar + optional final exam
C) 3 during the semestar + mandatory final exam
D) 3 during the semestar + optional final exam
E) 4 during the semestar + no final exam
Announcements/Reminders

Check the website for assignments and due dates.
Written HW #01 – Due Friday, September 29

MP HW #01 – Due Friday, September 29, by 11:59 pm.
(Course ID: GJ2016SPRING)


Reading assignment (check website) – Due on Friday.
Last class:
* Lenses (chapter 33).
Convergent lenses (thicker in the middle)
Divergent lenses (thinner in the middle)
* Images formed by refraction – Ray Tracing:
Convergent lens,
>f
Images formed by refraction – Ray Tracing :
Convergent lens,
<f
Images formed by refraction – Ray Tracing :
Divergent lens
QuickCheck
Light rays are converging to
point 1. The lens is inserted into
the rays with its focal point at
point 1. Which picture shows the
rays leaving the lens?
QuickCheck
Light rays are converging to
point 1. The lens is inserted into
the rays with its focal point at
point 1. Which picture shows the
rays leaving the lens?
Today:
* Thin-lens equation.
* Lensmaker's equation.
* Intro to waves (ch. 15)
Thin-lens Equation
Lateral Magnification
Sign convention for lenses
* f > 0, P > 0
* f < 0, P < 0
for convergent lens
for divergent lens
*d >0
for real image
(image on the other side of the object)
*d <0
for virtual image
(on the same side with the object)
*m>0
*m<0
for upright images
for inverted images
*R>0
*R<0
for convex side
for concave side
Example: (Problem 33-7 in the text)
It is desired to magnify reading material by a factor of 2.5 when
a book is placed 9.0 cm behind a lens.
(a) Draw a ray diagram and describe the type of image this
would be. (b) What type of lens is needed? (c) What is the power
of the lens in diopters?
Example: (Problem 33-7 in the text)
Lensmaker's Equation
By convention in this text:
*R>0
*R<0
for convex side
for concave side
Combination of lenses
Waves …
Waves …
Traveling disturbances
Transport energy, but not matter
See this link:
http://www.acs.psu.edu/drussell/Demos/waves/wavemotion.html
Transverse and Longitudinal Waves