PHY 112 Lab 9 Worksheet - Sofia Villamil Quintanar
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Rio Salado Community College *
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Course
112
Subject
Astronomy
Date
Dec 6, 2023
Type
docx
Pages
6
Uploaded by GeneralHare3811
PHY112 Lab 9
Name
: Sofia Villamil Quintanar
________________________
Radio Waves
Section
: 26190
_______
Download and run the
PhET Radio Waves and EM Field
simulation. Use the simulation to answer the
following questions.
1.
Select the following simulation settings: manual, full field, electric field, and static field. Record
your observations.
Move the electron down the antenna. Record your observations.
Move the electron back to its starting position. Change the setting from static field to radiated
field. Record your observations.
Move the electron down the antenna. Record your observations.
Change the simulation settings from manual to oscillate. Record your observations.
Analyze your observations, and draw some conclusions based on this information. Record your
conclusions in the last row on the data table.
Settings
Observations (be specific and detailed)
Static field, motionless
electron
The arrows are point towards the electron, the get bigger the
closer to the electron.
Static field, move electron
down the antenna
As the electron goes down the antenna the arrows also go
down as the electron does. The arrows being to increase in size
as they are passing and then they decrease in size as it moves
further away. The arrows stay pointing in the direction of the
electron.
Radiated field, motionless
electron
There are zero arrows when the electron is not moving.
Radiated field, move
electron down the antenna
As the electron begins to move downwards on the antenna,
the arrows point outwards from the electron in the opposite
direction.
Radiated field, oscillating
electron
The arrows are still oscilating but they do disappear. There is a
ripple effect that is slower than the manual setting. The electon
is going down the antenna and the goes up the antenna. All
the arrows are moving in the same direction.
Conclusions
The arrows will follow the electron, unless the electon is
moving then the arrows will come and then go away after the
electron stops moving in a radiated field.
2.
Select the following simulation settings: oscillate, full field, electric field, and radiated field.
Switch back and forth between the force on electron setting and the electric field setting. Pay
particular attention to the receiving antenna electron.
Complete the following table by filling in
either up, down, or zero for the directions.
Analyze your observations and draw some conclusions based on the observations. Record your
conclusions in the last row on the data table.
Position of electron in
receiving antenna
Direction of force on electron in
receiving antenna
Direction of electric field at
location of electron in receiving
antenna
Maximum
Down
Up
Minimum
Up
Down
Equilibrium (halfway
between max and
minimum positions
Zero
Zero
Conclusions
The direction of the force on the electron and the direction of the
field are opposite when the electron is at the max or at the min.
3.
Select the following simulation settings: manual, full field, electric field, and radiated field. Run
the simulation long enough so that there are no EM waves on the screen.
Check the box for electron positions. Change the simulation setting from manual to oscillate. Let
the simulation run for a bit, and then pause the simulation. Answer the following observation
questions:
Question
Answer
Do the transmitting and receiving antenna
electrons start moving at the same time? If not,
which one moves first? When does the other
start to move?
No the transmitting electron beings moving
right away, but the receiving electron does
not start moving until the arr
ows reach it.
When the transmitting electron is at its
maximum position, where is the receiving
antenna electron (e.g.,
max, min, zero, or some
other position)?
When the transmitting electron is at its max
so is the receiving electron.
Compare the time that it takes the transmitting
electron to complete one full cycle of motion to
the time it takes the receiving electron to
complete one full cycle of motion.
The transmitting electron moves faster than
the receiving electron.
Compare the distance the transmitting electron
travels in one full cycle to the distance traveled
by the receiving electron during one full cycle.
The transmittin
g electron also moves further
than the receiving electron.
4.
Use your observations in tables 1, 2, and 3 to explain the motion of the electron in the receiving
antenna. What causes it to move? Why does it change direction? How is this motion related to
the electron in the broadcasting antenna? Be specific and detailed. Use your observations to
support your discussion.
5.
Select the following simulation settings: oscillate, full field, electric field, and radiated field. Let
the simulation run long enough for the receiving antenna electron to begin oscillating. Pause the
simulation. Take a screen shot. Paste the screen shot into the space below.
The receiving electron moves slower and cover less amount of distance than the transmitting
electron. This is because
the transmitting electron is transmitting to much
to the receiving antennas
where as the receiving antenna is only receiving from one of the transmitting antennas.
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Answer the following observation questions based on the above picture.
Observation question
Answer
Roughly, how many electric waves
are present in the above picture?
15
How could you use this electric
field diagram to determine the
length of the electric waves?
I could use the frequency of the waves and c. I would use
the equation c=^f^=lambda
6.
Change the setting from full field to curve with vectors. Switch back and forth between force on
electron and electric field settings. What does the curved line in the curve with vectors setting
represent? Explain your reasoning.
The curved lines with the vectors represent the electromagnetic waves. The waves has a charge
from the electron in the transmitt
ing antenna and the electromagnetic wave then carries this
charge into the receiving antenna which creates a current.
7.
Select the following simulation settings: oscillate, curve with vectors, electric field, and radiated
field. Make the following changes, and observe the effect the change has on the wavelength,
frequency, and amplitude. Also, observe how this change affects the behavior of the motion of
both the transmitting and receiving electrons.
Reset the simulation between each system change (e.g., set the frequency back to its original
position before changing the amplitude).
Record your observations.
Analyze your observations, and draw some conclusions based on the observations. Record your
conclusions in the last row on the data table.
System
changes
Effect on the
wavelength
Effect on
number of
waves
between the
antennas
Effect on wave
amplitude
Effect on
transmitting
electron
behavior
Effect on
receiving
electron
behavior
Increase
the
frequency
Shorten
More waves
increase
Increase speed
Increase speed
Increase
the
amplitude
lengthens
Less waves
increase
decrease
decrease
Conclusion
s
The frequency and the amplitude have a very big effect on a wave, to increase the
speed you should increase the frequen
cy, and to decrease the speed you have to
increase the amplitude. The both of these effect will have the opposite reactions except
on the amplitude.
Summary and Reflection
Summarize the major findings of this exploration. What do you know now that you did not know before?
Be specific.
From th
is lab I can concluse that the transmitting antenna seems to do much more work than the
receiving antenna. It works much faster and travels a longer distance as well. Changing the frequency
vs changing the amplitude tends to have the opposite effect on a system, except when it comes to the
amplitude. Field lines will work in the opposite direction as the force on an electron.
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