Optics 1 Name: ____________________ Date: _____________________ Part 1. From the Previous Lab 1. A beam of light shines through air when it hits another medium at an angle of 𝜃1 = 30° from the normal. The second medium which the light propagates through is unknown but the velocity of light as it propagates through this medium is 𝑣 = 2 ∙ 103 𝑚 𝑠⁄ . The setup is shown below: a. Determine the index of refraction of the second medium b. Determine the refracted angle 𝜃2 2. A laser shines some light onto a diffraction grating with a grating pattern of 𝑑 = 1 400 𝑚𝑚 𝑠𝑙𝑖𝑡𝑠 . The first maximum occurs at x = 0.3cm from the m = 0 maximum. If the distance between the grating and the screen it shines on is 10cm, what is the wavelength of the light? Optics 2 Part 2: Optics: Based on our own intelligence, the clear window ports in the Zenit-8 capsule appear to be about 15 inches across. To include some buffer for mounting, let us assume the aperture (lens diameter) of the camera is 12 inches diameter. The bigger the aperture of a camera, the more light it collects and the brighter the image becomes. However, if the focal length also increases, then the magnification increases and the light is spread over more pixels (meaning individual pixels now collect less light). Because image brightness is affected by both aperture size and focal length, camera systems are often characteriszed by their focal ratio. If you have any experience with photography this is the “f-number” or “f-stop” designated by f/#. Focal ratio is simply 𝑓/# = 𝐹𝐿 𝐷 Where FL is the focal length and D is the aperture diameter, both in the same units (m). 1. What is the focal ratio of the Zenit-8 camera? __________________ 2. Is this large, or small, or reasonable compared to a standard commercial camera? If you’re not sure, try asking a friend, or searching for common focal ratios found on camera lenses. Optics 3 Part 3: Working with Thin Lens 2. There is a system of two lenses shown below with a table of attributes describing the system Lens 1 Lens 2 𝑓1 = 10𝑐𝑚 𝑓2 = 10𝑐𝑚 𝑝1 = 30𝑐𝑚 𝑝2 = ? 𝑞1 =? 𝑞2 =? 𝑑 = 35𝑐𝑚 Calculate the unknown values in the table. “d” is the distance between the lenses. Start from left and apply the thin lens equation and go towards the right. a. What is the magnification of the last image? b. I’ve depicted an inverted stickman as the ending image, is this accurate? PS 115L Homework 8 1 Name: ____________________ Date: _____________________ 1. In St. Augustine there are alleged ghosts. During the night, there is an unknown frequency which emits from unknown sources in the air. A scientist decides to investigate what the frequency is by going near the source of the noise and holding a closed end tube (much like the one in the lab) and measuring

1. Optics
1
Name: ____________________
Date: _____________________
Part 1. From the Previous Lab
1. A beam of light shines through air when it hits another
medium at an angle of �1 = 30° from the
normal. The second medium which the light propagates through
is unknown but the velocity of
light as it propagates through this medium is � = 2 ∙ 103 � �⁄ .
The setup is shown below:
a. Determine the index of refraction of the second medium
b. Determine the refracted angle �2
2. A laser shines some light onto a diffraction grating with a

2. grating pattern of � =
1
400
��
�����
. The first
maximum occurs at x = 0.3cm from the m = 0 maximum. If the
distance between the grating and
the screen it shines on is 10cm, what is the wavelength of the
light?
Optics
2
Part 2: Optics:
Based on our own intelligence, the clear window ports in the
Zenit-8 capsule appear to be about 15 inches

3. across. To include some buffer for mounting, let us assume the
aperture (lens diameter) of the camera is
12 inches diameter.
The bigger the aperture of a camera, the more light it collects
and the brighter the image becomes.
However, if the focal length also increases, then the
magnification increases and the light is spread over
more pixels (meaning individual pixels now collect less light).
Because image brightness is affected by
both aperture size and focal length, camera systems are often
characteriszed by their focal ratio. If you
have any experience with photography this is the “f-number” or
“f-stop” designated by f/#. Focal ratio is
simply
�/# =
��
�
Where FL is the focal length and D is the aperture diameter,
both in the same units (m).
1. What is the focal ratio of the Zenit-8 camera?
__________________

4. 2. Is this large, or small, or reasonable compared to a standard
commercial camera? If you’re not
sure, try asking a friend, or searching for common focal ratios
found on camera lenses.
Optics
3
Part 3: Working with Thin Lens
2. There is a system of two lenses shown below with a table of
attributes describing the system

5. Lens 1 Lens 2
�1 = 10�� �2 = 10��
�1 = 30�� �2 = ?
�1 =? �2 =?
� = 35��
Calculate the unknown values in the table. “d” is the distance
between the lenses. Start from left
and apply the thin lens equation and go towards the right.
a. What is the magnification of the last image?
b. I’ve depicted an inverted stickman as the ending image, is
this accurate?

6. PS 115L
Homework 8
1
Name: ____________________
Date: _____________________
1. In St. Augustine there are alleged ghosts. During the night,
there is an unknown frequency which
emits from unknown sources in the air. A scientist decides to
investigate what the frequency is by
going near the source of the noise and holding a closed end tube
(much like the one in the lab)
and measuring where the nodes are. The scientist hears higher
frequencies at d110cm,
d2 = 28.2cm and d3 = 53cm. The measurements follow the
diagram below:
a. What is the average of the wavelengths that the scientist
found?
b. Using v = 340 m/s, and the average wavelength, what is the

7. frequency the unknown sources emit?
PS 115L
Homework 8
2
2. The figure below shows water going through a pipe. The
diameter of �1 is three times the
diameter of �2. What is true about the velocity of �1 ���
�2? Show work which leads to the
correct answer.
a. �1 = 3�2
b. �2 = 9�1

8. c. �2 = 3�1
d. �1 = 9�2
PS 115L
Homework 8
3
3. Look at the following figure of the airflow apparatus (Venturi
tube). The arrows represent airflow
inside a tube. With the information given and ���� =
1.2��/�
3 ; ������ = 1000��/�
3: Find �1,

9. �2 ��� ∆ℎ.