Name: ______________________________________ Date: ________________________
Student Exploration: Ray Tracing (Mirrors)
Vocabulary: concave mirror, convex mirror, focal point, magnification, real image, reflect, virtual
image
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
For these questions, it would be helpful to have a metal spoon on hand. If you don’t have one,
try to imagine looking at yourself in a spoon.
1. Look at yourself in the front of the spoon (the side where the food sits). What do you see?
My face is upside down
The front of a spoon is an example of a concave mirror.
2. What do you see when you look at yourself in the back of a spoon? My face is right side up
The back of a spoon is an example of a convex mirror.
Gizmo Warm-up
The Ray Tracing (Mirrors) Gizmo™ shows a side view
of a light bulb positioned to the left of a mirror. Light rays
passing from the light bulb to the mirror are shown.
To begin, select the Concave mirror. Turn on Colorize
lines. Under Show lines, turn off the Central line and
the Line through focal point so that only the Parallel
line is showing.
1. The blue dot in front of the mirror is the focal point of the mirror. Move the light bulb on the
left around. What is always true about the ray that is reflected from the parallel ray?
The reflected ray goes through the focal point
2. Turn off the Parallel line and turn on the Line through focal point. Move the light bulb
around. What do you notice about the reflected ray in this situation?
The reflected ray is always straight
This study source was downloaded by 100000835361505 from CourseHero.com on 02-14-2022 13:55:14 GMT -06:00
https://www.coursehero.com/file/32234982/M10-L2-PA1-Gizmodoc/
, Get the Gizmo ready:
Activity A: Check that the Concave mirror is selected.
Turn on the Parallel line, Central line, and Line
Real and virtual
through focal point.
images
Place the light bulb above -24 on the central axis,
with the focal point at -12.
Introduction: A concave mirror is also called a “converging mirror” because it reflects light rays
into a point. A real image is formed where the reflected light rays converge at a point. Unlike a
virtual image that forms behind a mirror, a real image can be projected onto a screen.
Question: How do mirrors create real and virtual images?
1. Observe: In its current configuration, the distance from the light bulb to the focal point is
slightly more than 12 units. The distance from the focal point to the mirror is exactly 12 units.
A. What do you notice about the size of the light bulb’s image? It’s the same size
B. What do you notice about the orientation of the light bulb’s image? Its upside down
2. Investigate: Complete each action described in the table below, and state how that action
affects the image.
Action Effect on image
Move the light bulb to the left. Bulb goes to the right, gets smaller
Move the light bulb to the right. Bulb goes to the left, gets bigger
Move the focal point to the left. Bulb moves to left, gets bigger
Move the focal point to the right. Bulb moves to the right, gets smaller
3. Analyze: Examine the results recorded in your table.
A. In general, how do the size and position of the image change when the distance
between the light bulb and the focal point increases?
The farther away the bulb is from the focal point, the larger the image
B. In general, how do the size and position of the image change when the distance
between the light bulb and the focal point decreases?
The closer the bulb is to the focal point, the smaller the image
(Activity A continued on next page)
This study source was downloaded by 100000835361505 from CourseHero.com on 02-14-2022 13:55:14 GMT -06:00
https://www.coursehero.com/file/32234982/M10-L2-PA1-Gizmodoc/
Student Exploration: Ray Tracing (Mirrors)
Vocabulary: concave mirror, convex mirror, focal point, magnification, real image, reflect, virtual
image
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
For these questions, it would be helpful to have a metal spoon on hand. If you don’t have one,
try to imagine looking at yourself in a spoon.
1. Look at yourself in the front of the spoon (the side where the food sits). What do you see?
My face is upside down
The front of a spoon is an example of a concave mirror.
2. What do you see when you look at yourself in the back of a spoon? My face is right side up
The back of a spoon is an example of a convex mirror.
Gizmo Warm-up
The Ray Tracing (Mirrors) Gizmo™ shows a side view
of a light bulb positioned to the left of a mirror. Light rays
passing from the light bulb to the mirror are shown.
To begin, select the Concave mirror. Turn on Colorize
lines. Under Show lines, turn off the Central line and
the Line through focal point so that only the Parallel
line is showing.
1. The blue dot in front of the mirror is the focal point of the mirror. Move the light bulb on the
left around. What is always true about the ray that is reflected from the parallel ray?
The reflected ray goes through the focal point
2. Turn off the Parallel line and turn on the Line through focal point. Move the light bulb
around. What do you notice about the reflected ray in this situation?
The reflected ray is always straight
This study source was downloaded by 100000835361505 from CourseHero.com on 02-14-2022 13:55:14 GMT -06:00
https://www.coursehero.com/file/32234982/M10-L2-PA1-Gizmodoc/
, Get the Gizmo ready:
Activity A: Check that the Concave mirror is selected.
Turn on the Parallel line, Central line, and Line
Real and virtual
through focal point.
images
Place the light bulb above -24 on the central axis,
with the focal point at -12.
Introduction: A concave mirror is also called a “converging mirror” because it reflects light rays
into a point. A real image is formed where the reflected light rays converge at a point. Unlike a
virtual image that forms behind a mirror, a real image can be projected onto a screen.
Question: How do mirrors create real and virtual images?
1. Observe: In its current configuration, the distance from the light bulb to the focal point is
slightly more than 12 units. The distance from the focal point to the mirror is exactly 12 units.
A. What do you notice about the size of the light bulb’s image? It’s the same size
B. What do you notice about the orientation of the light bulb’s image? Its upside down
2. Investigate: Complete each action described in the table below, and state how that action
affects the image.
Action Effect on image
Move the light bulb to the left. Bulb goes to the right, gets smaller
Move the light bulb to the right. Bulb goes to the left, gets bigger
Move the focal point to the left. Bulb moves to left, gets bigger
Move the focal point to the right. Bulb moves to the right, gets smaller
3. Analyze: Examine the results recorded in your table.
A. In general, how do the size and position of the image change when the distance
between the light bulb and the focal point increases?
The farther away the bulb is from the focal point, the larger the image
B. In general, how do the size and position of the image change when the distance
between the light bulb and the focal point decreases?
The closer the bulb is to the focal point, the smaller the image
(Activity A continued on next page)
This study source was downloaded by 100000835361505 from CourseHero.com on 02-14-2022 13:55:14 GMT -06:00
https://www.coursehero.com/file/32234982/M10-L2-PA1-Gizmodoc/
