Page 252-253
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What type of lens can make parallel rays converge or
come together? Page 214
Convex lenses make parallel rays converge.
What type of lens always makes parallel rays diverge, or
spread out? Page 214
Concave lenses make parallel rays diverge.
Copy the following diagram of convex lenses in your
notebook. For each complete a ray diagram using three
rays. Describe the characteristics of the image. Page 220
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When the object is more than twice as far from the convex
lens as the focal point , the characteristics of the image are
the following:
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Smaller than the object
Closer to the lens than the object
Inverted
Real
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SEE LAST DIAGRAM PAGE 220
b. When the object is between the convex lens and the focal
point the characteristics of the image are the following:
page 220
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larger than the object
farther from the lens than the object
upright
virtual
SEE FIRST DIAGRAM PAGE 220
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a. Which type of lens, convex or concave, should a
person who is near-sighted use? Explain.page 228
A person who is near-sighted should use a concave lens, which
helps diverge the parallel rays slightly so that the image forms on
the retina, instead of in front of it.
4. b. Which type of lens, convex or concave should a
person who is far- sighted use? Explain. Page 234
A person who is far-sighted should use a convex lens, which helps
converge the light rays so they come into focus on the retina,
instead of in behind it.
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Draw a diagram showing the mirror and lens arrange
in a reflecting telescope.
SEE diagram page 245 diagram 6-28

A. Explain how focusing occurs in a microscope. Page
245
In a microscope the object being viewed is moved closer to or
farther from the objective lens until it comes into focus.
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B. Explain why this type of focusing would not work
for a telescope.
This type of focusing does not work for a telescope because the
distance of the object being observed cannot be moved farther
from or closer to the telescope.
11. Explain why mirrors have one focal point but lenses have
two focal points. Describe the relationship between the
two focal points of a lens. page 218
Unlike mirrors, light can pass on either side of a lens. As a result
mirrors have only one focal point, while lenses have two focal
points. The two focal points are located on each side of the lens
and are always the same distance from the lens.
13. One type of lens can produce an image that is inverted,
real, larger than the object and farther from the lens than
the object. Is this lens convex or concave? Where is the
object relative to the focal point. Sketch a ray diagram that
verifies your answer.
This type of lens that produces an image that is inverted, real,
larger than the object and farther from the lens than the object is
a convex lens. The object is located between the focal point and
twice the focal length.
See diagram page 220 middle diagram
Questions pages 259-261
#2
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FALSE – The amplitude of a wave is the distance between
the wave crest and the rest position /equilibrium position.
TRUE
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FALSE – An opaque material prevents light from penetrating
the object.
TRUE
FALSE - Diffuse reflection scatters light, preventing the
formation of an image.
FALSE - The angle of reflection is the angle between the
reflected wave and the normal to the reflecting surface.
TRUE
FALSE - A concave mirror cause light rays to converge
toward a focal point. Or a convex mirror causes light rays to
diverge.
FALSE – Concave mirrors always converge light rays and can
form images that are real.
FALSE – When a ray passes from a less dense medium to a
more dense medium, the ray bends toward the normal. Or
when a ray passes from a more dense medium to a less
dense medium, the ray bends away from the normal.
FALSE – Far–sighted vision results when light rays produce
an image behind the retina. Or, near-sighted vision result
when light rays produce an image before they reach the
retina.
FALSE – Concave lenses always form virtual images.
m. FALSE – Microscopes and telescopes both have objective lens.
n. FALSE – A refracting telescope is made of a combination of
lenses. Or a reflecting telescope is made of a combination of
lenses and mirrors.
3. Describe one situation in which early technologies
involving light made new scientific discoveries possible.
Page 133-134
The invention of the microscope allowed scientists to study the
microbial world. The development of the telescope allowed
scientist to view the components of outer space in detail.

Draw a light wave . Label amplitude, wavelength
trough, and crest.
See diagram page 140 – diagram 4.13

Explain how a prism affects white light that passes
through it. Page 149
A prism causes the white light to refract and separate into its
component colors: red, orange, yellow, green, blue, indigo, and
violet.

How do transparent and translucent materials differ
when light strikes them? Page 174
Transparent materials allow light to pass through without any
change in direction.
Translucent materials allow light through but scatters it in every
direction.

Explain why light, but not sound can travel through a
vacuum. Page 136
Light is electromagnetic radiation and can travel through a
vacuum but sound waves depend on particles and cannot.

Describe one application of microwaves and one
application of x-rays. pages 159 & 163
Microwaves – microwave ovens, satellite communications,
airport radar transmitters and receivers.
X-rays – medical imaging, airport security scanning machines.

State the law of reflection. Page 178
The law of reflection states that the angle of reflection is equal to
the angle of incidence.

How can light rays that are involved in both specular
and diffuse reflection all follow the law of
reflection.page 178
In specular reflection all incident rays hit the flat smooth surface
with the same angle of incidence, so they all reflect at the same
angle of reflection. In diffuse reflection, the angles of incidence
for the rays are different because the surface is rough, so their
corresponding angles of reflection are also differ. Whether the
surface is smooth or rough, each individual ray that strikes the
surface obeys the law of reflection.

Make a sketch to show you would find the focal point
for a convex mirror.page 204 & 205
The focal point for a convex mirror is behind the mirror. To find
its location, draw incident rays parallel to the principal axis, and
extend the reflected rays behind the mirror until they meet.
See diagram page 204 - Figure 5-32
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
Explain the difference between real and virtual
images.
A real image is an image formed when reflected rays meet.
If you put a screen at that location, the image would appear
on the screen. A virtual image is an image formed by the
extension of the reflected rays. The light rays only appear to
be coming from the image.
19. How does the distance of the object from a concave
lens affect the image? For example , as the object moves
farther from the lens, what happens to the characteristics
of the image?
As the object moves farther from a concave lens, its image
becomes smaller and moves a little bit farther from the lens (but
it is still closer to the lens than the object)
25. Summarize two use of the invisible spectrum in
producing medical images of the human body.
X-rays are absorbed better by bone than by tissue, which allows
an image of a skeleton to be formed. Very sensitive x-ray
procedures can also differentiate between different types of
tissues.
Radio waves are used in conjunction with strong magnets to
make an image of different tissues and bones. The technique is
called MRI or magnetic resonance imaging.
32. Examine the ray diagram below in which the green and
blue regions represent different media. Which medium is
more dense? Explain.
The green medium (A) is more dense than the blue medium (B)
because the light is refracted away from the normal as it travels
from A to B