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Tuesday, November
Entry Task
Take the next couple of
minutes to study for your
test
th
13
Schedule:
• Chapter 17 Test
Objective:
•I can be assessed on
important information about
the electromagnetic spectrum
You will do the following
today:
Homework
1. Take the test
• Chapter 18 introduction
2. Turn in the test
3. Get a chapter 18 intro and • Read/RSG 18.1
a 18.1 RSG
4. Work on these, they are
due tomorrow
Wednesday, November 14th
Entry Task
Write down the following and
then name the term
described by each.
1.
2.
3.
4.
Schedule:
• 18.2 Read
• 18.2 Notes Packet
Objective:
• I can understand that
How a light wave bends when
lenses for images by
it enters a new medium at an
refracting light
angle
Homework:
How a light wave bounces
• Finish note packet
back when it hits a barrier
The type of wave visible
Please have on desk:
light is
• Work from yesterday will
What mirrors do to light
be checked off tomorrow
waves to form images
Thursday, November 15th
Entry Task
Schedule:
• Mirrors and Lenses Notes
Write down each definition
and match it with the correct
term.
1. A picture of an object
formed by light rays
2. The point where parallel
light rays striking a concave
mirror meet
3. A surface that curves out
like the back of a spoon.
Objective: I can understand
that mirrors for images by
reflecting light and that
lenses form images by
refracting light
Terms: concave, convex, focal
point, optics, image
Homework
• 18.2 RSG
Please Have on Desk
• Chapter 18 Introduction
• 18.1 RSG
• 18.2 Notes packet
Plane Mirrors
1. Look at the shiny side of the foil
How clear is the image produced by the mirror (Use
a 0-4 scale with 4 being perfectly clear and 0
being no image visible)? Why is this the case.
2. Look at the dull side of the foil
How clear is the image produced by the mirror (Use
a 0-4 scale with 4 being perfectly clear and 0
being no image visible)? Why is this the case.
3. Lightly crumple the foil and then flatten it
again
How clear is the image produced by the mirror (Use
a 0-4 scale with 4 being perfectly clear and 0
being no image visible)? Why is this the case.
Reflection
Plane Mirrors
normal
angle of
incidence
angle of
reflection
60°
60°
REGULAR REFLECTION
Diffuse Reflection
Concave Mirror
Convex Mirror
Lenses form images by
refracting light
A medium can refract light
• Refract: the bending of a wave as it
crosses the boundary between two
mediums at an angle other than 90
degrees.
– Mediums: air  lens  air
– Occurs because one side of the light wave
reaches the new medium (lens) slightly before
the other side does.
– That side changes speed, while the other
continues at regular speed, causing it to turn.
Refraction of light
• Direction in which a light wave
turns depends on whether the
new medium slows the wave
down or allows it to travel
faster.
– Denser medium-slow down
– Thinner medium-speed up
• The normal- imaginary line
perpendicular to the new
surface that helps describe
refraction
– If the medium slows the wave, the
wave will turn toward the normal.
– If the medium lets the wave speed
up, the wave will turn away from
the normal.
Refraction and Rainbows
• Rainbows are cause by
refraction and reflection
of light through spherical
water drops which act as
prisms.
– Like a prism, water drops
separate the wavelengths
of sunlight to produce a
spectrum.
– Unlike a prism, only one
color reaches your eye
from each drop.
• Red appears at the top of
a rainbow because it is
coming from higher drops
• Violet comes from lower
drops
Shape determines how lenses form
images
• Flat mediums- produce a clear image on
other side
• A lens is a clear optical tool that refracts
light- non flat mediums.
– Different lenses refract light in different ways
– These different images formed are useful for
a variety of purposes
• Types of lenses: convex and concave
Convex Lens
• Curved outward
• Parallel light rays passing through a convex lens are
refracted inward.
– They meet at a focal point on the other side of the lens
– Rays refract twice: when entering the new medium and when
leaving the new medium.
– Rays on the outer part of the lens are refracted the most
– Rays on the principal axis-the line joining the center of the two
curved lenses- will go straight through and not refract.
focal point
principal axis
Concave Lens
Principle Axis
• The lens is curved inward.
• Parallel light rays that pass through a concave lens are
refracted outward.
– Rays do not ever meet.
– Rays refract twice: when entering the new medium and when
leaving the new medium.
– Rays on the outer part of the lens are refracted the most
– Rays on the principal axis-the line joining the center of the two
curved lenses- will go straight through and not refract.
Images formed by lenses
• Type of image depends
on
– Lens type
– For convex lenses: the
distance between the lens
and the object.
• Convex lens: Distance
from lens is measured in
focal length- the distance
from the center of the
lens to the lens’s focal
point.
How Convex Lenses Form Images
• Look at the 3 steps below to see how an image is
formed by a convex lens. Step 1 is repeated from
the previous slide.
Convex Lenses
Bigger? Smaller? Flip-Flop?
• If the object is more than two focal lengths
away, the image will be upside down and
smaller.
• If the object is between 1 and 2 focal
lengths away the image will be upside
down and larger.
• If an object is less than one focal length
away it will appear right side up and
larger.
Concave Lenses
• Always right side up and smaller than
normal appearance.
• Distance between lens and object does
not make a difference.
Friday, November
Entry Task
Do the following using your
own words
1. Define Focal Point
2. Define Focal Length
3. Define Lens
th
16
Schedule:
• Looking at Mirrors and
Lenses Lab
Objective:
•I can understand that lenses
form images by refracting light
Homework
• Read/RSG 18.3
Please have on desk:
• 18.2 RSG