Download Semester Project S 17

Class Project
Physics 1010-400, Physics 1010-401
Spring 2017
Every general education class at SLCC, including physics 1010, requires a signature
assignment (special assignment) and a reflective writing essay about the signature
assignment to be posted on the student’s ePortfolio web page.
The signature assignment for Physics 1010-400 and Physics 1010-401 for Spring
2015 consists of several parts, each of which must be done:
1) Star Identification
16 points
2) Equation Analysis
26 points
3) Learning about a Law of Physics
12 points
4) Explanation of Fermi’s Paradox and possible resolution
16 points
70 points total
The Reflective Writing essay is about your signature assignment. It should be
presented as a coherent whole (an essay not just a list of answers to questions). It,
along with your project, should be put on an ePortfolio page. When you send me the
URL of that page of your ePortfolio I will go online and grade your reflective writing and
project presentation.
This is worth an additional 30 points.
There is more information about how to set up an ePortfolio page and what the
reflective writing essay should include at the end of this document and in the syllabus.
As far as length, your reflective writing essay should be a couple of pages of well
organized text at the minimum. Structure this essay so it is coherent and makes sense
as a whole; don’t just list a series of questions and anwers.
The Signature Assignment Parts
Part 1: Star Identification:
The photo below is of the centaurus/southern cross region of the milky way. This is not
visible in our sky as our latitude on the Earth is too far north. These are starfields seen
generally in the southern hemisphere and some of the tropical latitudes of the northern
hemisphere.
Centaurus is a large constellation in terms of the area it covers. The easiest markers in
this constellation are the two brightest stars, alpha and beta centauri. These are the two
brightest stars in the photo and are located just under the center of the photo. Alpha
Centauri is yellow and Beta Centauri is blue. Alpha Centauri is the nearest star system
to our own. Were we living in the Alpha Centauri system, looking back towards the Sun,
the Sun would look much like Alpha Centauri does from here.
If you draw a line from Alpha Centauri through Beta Centauri and move, from Beta
Centauri about 2.5 times the Alpha Centaure/Beta Centauri distance you will see a
bright red star. That bright red star is one of the stars of the Southern Cross.
Pick 4 of the stars in the photograph below. Label each of these stars on the photo.
Then tell me the following things about each star:
1) Its name
2) Distance from Earth in light years (a light year is how far light can travel through the
vacuum of space moving at 670 million miles per hour for a year. By everyday
standards a light year is an enormous distance)
3) When the light from the star now visible in the skies of Earth actually left the star (if a
star is 10 light years away its light now visible in the skies of Earth left that star 10 years
ago in 2002)
4) Its size compared to the Sun (you can do the comparison using the star’s radius to
the Sun’s radius or the star’s volume to the Sun’s volume)
5) The star’s luminosity compared to the Sun (luminosity is a measure of brightness)
You can list this information in tabular form star by star. A little extra credit will be
available for identifying the coal sack in the photo.
A good way to proceed is to use the star chart (also attached) to identify the stars by
their greek letters or proper name and then do a net search on the names to find
information.
Alpha Centauri, Beta Centauri, Gacrux, Delta Crucias, Acrux, Mimosa.
I’ve included an image of the Australian flag as a point of interest.
Above: photo of the Centaurus/Crux (Southern Cross) sector of the milky way.
Australian flag with the Southern Cross on the
Centaurus/Southern Cross
right and Beta Centauri in the lower left
star chart with Alpha and
Beta Centauri on the left
Acrux (Alpha Crucis)
It’s distance is 321.98 light years from earth. The star is larger than the sun with a
radius of 2050490.98 miles. It’s absolute magnitude is -4.2.
Mimosa (Beta Crucis)
Is 278.53 Light years away. This star has a radius of 2048799.79 miles. And it’s
absolute magnitude is -3.41
Delta Crucis
This star is 278.53 light years away. It has a radius of 1593347.07 miles. It’s absolute
magnitude is -2.33.
Gacrux (Gamma Crucis)
This star is the closest. It is only 88.56 light years away from us. This star’s radius is
2050490.98. It’s absolute magnitude is -4.2.
Part 2: Equation Analysis:
These equations are in your textbook so that should be a good source of accurate
information about them.
Equation 1: E = mc2
Answer or do the following:
Question 1: Find out what the things in this equation (using your book or a net search
will do it) are and identify them as either variables or constants.
Question 2: What is the size of c2?
C^2 is the speed of light squared. Which is represented as (3.00*10^8)^2
Question 3: Are mass and energy related? Answer yes or no and then provide a brief
explanation of your answer based on the analysis of the equation.
Yes, the energy is equal to the mass. The greater the mass, the greater the energy.
Question 4: Analyze the statement: “if it is possible to change mass into energy a little
bit of mass could produce a lot of energy”. Is it true or not? Provide a brief explanation
based on your analysis of the equation
Yes, because if you increase the mass the energy will also be increased. Because
mass is multiplied by the speed, the increase of mass would have a great effect on the
energy.
Equation 2: d = gt2/2
…where:
d = distance an object falls when released from rest (no air resistance)
g = acceleration of gravity at the Earth’s surface
t = time the object has been falling
Question 5. Which of the following statements do you agree with and why? Use the
equation to support your answer (you can also refer to the learning from equations
module files).
a) heavy objects fall faster than lighter objects
b) objects fall at the same speed (if no air resistance) and weight doesn’t matter.
I must agree with “b”. This is because gravity has an equal effect on all objects in
regards to their falling. Since gravity effects them the same regardless of mass, they
accelerate at the same rate.
Equation 3: v = gt
…where:
v = velocity of a falling object if released from rest (no air resistance)
g = acceleration of gravity at Earth’s surface
t = time the object has been falling
Question 6: Which of the following statements do you agree with and why? Use the
equation to support your answer (you can also refer to the learning from equations
module files).
c) heavy objects fall faster than lighter objects
d) objects fall at the same speed (if no air resistance) and weight doesn’t matter.
“d” Is correct this is because velocity is independent of weight. Velocity has to do with
the distance an object falls, not its weight.
Now go online and view this link. If the link is inoperable go to google video and do a
search on “Galileo hammer feather experiment”.
http://www.youtube.com/watch?v=4mTsrRZEMwA
Question 7: For most of recorded history, people thought that heavy objects naturally
and under all conditions fall faster than lighter objects. Why did it take us so long to
realize the true state of affairs?
Because the idea of heavier objects falling faster was a widely taught and accepted
idea. It was originally taught by Aristotle, and that idea was perpetuated by the catholic
church. This was the thought until it was disproved by Galileo.
Question 8: The Earth’s gravity DOES exert a greater force on heavier objects than
lighter ones (these forces are called weight). However, with no air resistance objects fall
at the same speed in a given gravity field. The weight difference can be thousands of
pounds to one and the objects still fall at the same speed. What physical property of
mass compensates for the difference in applied forces?
The physical property of larger mass that compensates is call inertia. It takes more force
to move and stop and object with a larger mass.
Equation 4: e = 1 – Tcold/Thot
…where:
e = efficiency of energy use
Tcold = the temperature of the environment surrounding the heat engine
Thot = the internal operating temperature of the engine
This is the equation for the efficiency of a heat engine (your car is a heat engine unless
you have an electric model). An e = 1 is 100% efficiency, meaning 100% of the energy
gets used to do what you want to do with no “wasted”, unrecoverable energy. An e = 0
is an efficiency of zero with none of the energy going to what you want to do and all of
the energy being “wasted” or in unrecoverable forms.
The temperatures in this equation are in the Kelvin scale where the lowest temperature
is 0 degrees. There are no negative temperatures in the Kelvin scale. A temperature we
might encounter on Earth would be about 300 degrees Kelvin.
Question 9: Is it possible to achieve 100% efficiency, in theory, by lowering the
temperature of the environment surrounding the heat engine (Tcold)? Why or why not?
It is possible in theory to have 100% efficiency. e=1 and the temperature of the cold was
0 kelvin.
Question 10: Is it possible, in practice, to achieve 100% efficiency by lowering the
temperature of the environment surrounding the heat engine (Tcold)? Why or why not?
No it is not possible to have a 100% efficiency in practice. This is because in any engine
there is a loss of energy through heat because of friction.
Question 11: Is it possible to achieve 100% efficiency, in theory, by raising the internal
operating temperature of the heat engine (Thot)? Why or why not?
No, because the cold and hot temperatures need to equal 0 to have 100% efficiency.
Question 12: Is it possible to achieve 100% efficiency, in practice, by raising the
internal operating temperature of the heat engine (T hot)? Why or why not?
No because you would have energy loss due to different reasons because of friction.
Also as stated above you wouldn’t be able to achieve that efficiency through an
increase of heat.
Question 13: If your car is not electric, it is a heat engine and is subject to the efficiency
equation. Is it possible to build a car, using any kind of burning fuel, that is 100%
efficient? Explain.
It is not possible to build an engine that is 100% efficient. There will always be a loss of
energy in some way. But we can try our best to build the most efficient engines we can.
Part 3: Learning about a Law of Physics
Pick any Law or Principle of Physics in your textbook and:
1. Give me an explanation of what it is and what it means.
Newton’s third law, for every action there is an equal and opposite reaction. Meaning
that there are always two forces acting on a given object that has force exerted on it.
2. Give me 3 examples in the real world involving the law or principle.
A gun shooting, when you shoot a gun. The powder that is ignited explodes propels a
projectile. This also causes the gun to kick back in equal force that is opposite to the
direction of the projectile.
When you sit on a chair, your weight exerts a force on the chair. The chair exerts and
equal and opposite force to hold you up.
Lifting weights is another example. When you lift a weight, you can feel the force of
gravity against you. For you to hold the weight you must have an equal force applied to
it otherwise you will drop it.
Part 4: Explanation of Fermi’s Paradox and possible resolution
This involves the possible existence of alien life in the Universe. A net search should
bring up some immediate information on the subject.
1. Clearly explain what this paradox involves and why it is a paradox.
Fermi’s paradox has to do with existence of intelligent life on other planets. It
concludes there is no intelligent life on other planets. This stands to reason
because there are estimated over 1000 planets like earth in the galaxy, with suns
much older than the earth. If we haven’t had any signs of intelligent life in our
galaxy yet. It is not likely that there is any. It stands to reason that if there our
planets like ours, that have intelligent life, that have been around a lot long than
us. Then they more likely have a more advanced technology. That would allow
them to communicate with beings within their galaxy, outside their solar system.
2. List and briefly explain (like in a paragraph for each) 4 possible resolutions to the
paradox.
I don’t think fermi’s paradox is without flaws. I think there are many resolutions. I
think that there is a good chance that there are intelligent life on other planets.
Considering the infinite size of the universe.
Maybe there seems to be no point of interest in our solar system. The intelligent life
from other planets sees no need in coming here. Because if there are advanced
intelligent life, they would probably gain little from us.
Other advanced life forms might view earth as primitive and wish to stay away for fear of
a savage response if contact was made. Which could be detrimental to life on earth.
Therefore they keep their distance until earth advances to point their ready for such
contact.
They could have the technology to do such exploration. But maybe their solar system
lacks needed resources to make such travel very hard. Therefore, they are limited by
their resources to reach out to us.
Maybe there is a cycle with all intelligent life. That they all kill each other eventually. It is
possible that there are other intelligent life forms in the galaxy that have been around a
lot long than us. It could be that they killed each other off into extinction through war and
famine. Maybe they had a nuclear war, or a meteor hit their planet.
Reflective Writing
Physics 1010-400 and 1010-401
Spring 2015
Your reflective writing essay will be about how you accomplished these assignments,
what you learned and how this fits into the general education experience at SLCC. It is
about your signature assignment but gets a separate grade of 30 points. It should be
done in essay form as a coherent whole, not just a series of answers to questions.
I will give you a grade on both the signature assignment and reflective writing essay
based on what I see on your ePortfolio page. This is your showcase so I urge you to do
a good job. Use pictures and drawings as needed. If you want to include video one of
the easier ways to do that is provide a link to a youtube site, although you can post
video directly to your ePortfolio site.
You will need to send me your ePortfolio url so I can give you your signature
assignment grade and your reflective writing grade. If you use a user name and
password, I will need those as well.
Internet use and copying:
The internet is a good source of material on some of these subjects so I encourage you
to use it. However, I expect you to explain any material you find there in your own
words. I don’t want anyone doing wholesale copying from the internet. Doing so will
result in a zero.
You do have my permission to work together with other students. However, I require
that you do your own work. Individual work that bears a great similarity to someone
else’s individual work will result in zeroes for everyone involved.
About Help:
I will help you with these things if you need it so feel free to contact me for that purpose.
I will usually not directly give you the answer you are seeking but I will do my best to
point you in the right direction by helping your understanding of the issues involved.
I will not proof rough drafts; the idea here is to get it right and do a good job the first
time. Make sure that what you put on your ePortfolio is your best effort.
Remember that I will not grade your signature assignment or your reflective writing until
I see them on your ePortfolio. Work not done and posted will get a zero.
I have tried to put this project together so you can learn about some interesting things in
physics and have some fun. When people have trouble it is usually because of not
asking for help or waiting until the last minute to get started.
How to do an ePortfolio page and Reflective Writing
The College requires that students in any general education class, such as Physics
1010, do a Signature Assignment accompanied by a reflective writing essay that then
must be put on a web page on the student’s ePortfolio.
The nature of the signature assignment is left up to instructors and in my classes using
the projects seemed to be a natural application.
I will grade your projects upon completion.
Your reflective writing, which will be about your signature assignment, I will grade
separately from your signature assignment. It is a college requirement that I must
see your reflective writing on your ePortfolio before I can grade it. Reflective
writing that does not get done or does not appear on your web page will get a grade of
zero.
It is your responsibility, when your reflective writing is complete, to post it on your
ePortfolio and send me the URL. If your ePortfolio is password protected, you must also
send me the password. I’ve got to see your reflective writing on your ePortfolio to give
you a grade. There is no wiggle room here.
What is ePortfolio? For those of you who are first timers, ePortfolio is a web page you
build to highlight your general education classes and, in one form or another, will be part
of your grade in any general education class. You can do this free of charge using any
of the following platforms:
www.weebly.com
www.wordpress.com
There are help pages at:
www.slcceportfolio.weebly.com
www.slcceportfolio.wordpress.com
You may first want to visit:
http://www.slcc.edu/gened/eportfolio
…and:
You can also get help with workshops at the SLCC libraries. For info:
http://www.slc.edu/??????
What should your reflective writing look like?
In general, this is an essay. Don’t just list the questions that follow with brief answers.
Your reflective writing should be a real composition and part of your grade will be how
well written it is.
What you should include in your reflective writing? We’ll you should do your best to
answer the following questions and also include anything else that you think is relevant:
-What principles of Physics are involved in your signature assignment? List each
one and show how it applies to your signature assignment in detail. Inclusion of
any mathematics is good.
-Include any possible pictures or video of your signature assignment. Explain
what everything is.
-If your signature assignment included calculations, include those and the results
with an explanation of what they are.
-Did your experience with your signature assignment increase or decrease your
interest in Physics?
-What part of the signature assignment was most challenging and how did you
handle it?
-If you worked with others, how did this experience help you (if it did)?
-How does your performance on this assignment demonstrate achievement of –or
progress toward- SLCC’s college-wide learning outcomes?
-How does this signature assignment connect with what you learned in other
gened courses?
-What process did you go through to complete this signature assignment?
-What impact did this signature assignment have on you or your understanding
of the world? Did it challenge any of your assumptions?
-How does this signature assignment illustrate the growth you have had in this
class?
Be specific whenever possible. Avoid vague generalities such as “I really learned a lot”.
Appearance:
Make your signature assignment, reflective writing and ePortfolio look good. This kind of
internet presentation is likely to get more prevalent so a well-organized and visually
pleasing ePortfolio page is a good idea. You can use the pictures I have given here,
other pictures that are public domain on the internet and diagrams or art that you make.
It is also OK to include links to relevant and interesting sites on the internet.
This is your showcase so you should do everything you can to make it shine.
I can also help you but keep in mind it is a good idea not to wait until late in the
semester when I will be evaluating and grading over dozens of these. Also,
remember that I have to see all this online to grade it so you will need to send me
the appropriate URL.
If you work in a group, I expect your Reflective Writing Assignment to be done by
you personally and to be in your own words!