Slinky Physics Experiment

For our experiment we chose to look at the physics of slinkys in a fun and interesting examples. For materials we used 6 text books, a stopwatch, a weight scale, ruler, 2 different slinkys of different size and mass.

Physics Lab: Slinky Physics and Motion (Handout)

Purpose: To look at the correlation between how the size and weight of an object affect its speed.

Background: Translational momentum is the product of the mass and velocity of an object where (p=mv). Similar to velocity, linear momentum is a vector quantity where the magnitude of the vector is the distance between the two points and includes the direction of displacement from point A to B which will be showcased in the below experiment. According to Newton’s 2nd Law, the rate of change of the momentum of a particle is relative to the resultant force acting on the particle and is in the direction of that force. In this case the direction will be a gravitational pull at a falling 90 degree angle.  Mass is the dependent variable in the experiment where the heavier the mass, the faster it will travel when the same momentum is given.  Heights from which the object falls will also be altered to see if the correlation between the size and mass of the object is changed as heights increase or decrease as well. From a sustainability standpoint, the correlation between size and mass and its speed is applicable to many energy concepts like the size and mass of a car model altered to improve its optimal speed and fuel efficiency.

 

Procedure:

  1. Stack six books like stairs
  2. Measure the height of the books and the height of the incline
  3. Determine the mass of each slinky
  4. Put the slinkys one end at the top of the stack and the other end on the next step
  5. Push the slinky with the same momentum force each trial and track the speed of how long it takes to “walk” down the books
    1. Release the slinkys over the “steps” when it is at the 90 degree angle and the gravitational pull of momentum is pulling the slinky down the steps
  6. Do this 3-5 trials
  7. Vary the height of the book steps by taking away one or two books and do 3 trials at these heights
  8. Calculate velocity: d/t
  1. Using equation P=MV where P is momentum (mass and motion), M is the mass and V is the velocity, the equation shows that momentum is directly proportional to an objects mass and directly proportional to an objects velocity.
  2. Record trials in data formatting on the lab handout

Data:

Smaller slinky:

Mass (g)  207

Distance(Trial 1):  .23m Distance (Trial 2)   .23m Distance (Trial 3)  .23m
Time in seconds:   1.1 Time in seconds:  1.1 Time in Seconds:  1.1

 

Larger slinky:

Mass (g) 124.5

Distance(Trial 1):  .23m Distance (Trial 2)  .23m Distance (Trial 3)  .23m
Time in seconds:   1.8 Time in seconds:  1.7 Time in Seconds:  1.8

Velocity: 0.23 m/1.1 seconds = 0.21 m/s ( smaller slinky, mass: 207 grams)

Velocity: 0.23 m/ 1.77 seconds = 0.13 m/s (larger slinky, mass: 124.5 grams)

*Put into excel for graphical representation

Analysis:

Do the different masses of the slinkys change the velocity?

Yes

a)      If so why do you think this is true?

The slinky with the greater mass of 207 grams traveled faster at 0.21 m/s. The heavier the mass, the faster the slinky traveled down the “steps” With the compression and longitudinal waves that the slinky has in movement, the heavier mass gets pull down at a higher speed because of the natural momentum of gravitational pull that pulls the heavier mass down the “steps” at a faster rate.

Below is a graphical representation of the velocity and mass

slinky physics graphs

*Factors contributing to slinky movements: Longtiudinal waves, compression, mass and the momentum of gravitational pull*

 

 

Doing this experiment with students from the other class was a great learning experiment. They all participated willingly and ended up getting the same results we got and understanding why our hypothesis was correct. Learning from their experiments as well was a perfect way to integrate everything we have learned over the semester and really tied everything together. We got to cover so many variables in sustainability from simple laws of physics , to photovalactic cells, and greenhouse effects.



Tom Vale Presentation

 

 

 

We were lucky enough to have a special presentation by electrical engineer, Tom Vale, this past week in class. He started off with discussing how alternative fuels and energy are going to have to be the end to a means in the future because we are just wasting it now and burning it all up. Alternative energy methods date back hundreds of years ago and Tom started showing us some simplistic devices that can power engines without burning up fuel.

The first device he showed us was the Peltier device. He was an 1834 physicist who used 2 dissimiliar metals togethr to create electrical energy into junction. One side of the device would be in hot water, and the other in cool which would generate electricity and cause the bars on top of the device to turn. This became known as the Peltier effect. In scientific terms, a current is made to flow through a junction made of materials, A and B, heat is generated in the upper junction, and absorbed at the lower junction. Thermoelectric heat pumps showcase this effect as well as thermoelectric cooling devices.

He then discussed the Stirling Engine, developed by Robert Stirling in 1816 where he created this to eliminate steam engines.Steam engines were extremely dangerous and many explosions of them caused death and serious injury among maritime workers. The Stirling engine is a heat engine that is operated by a cyclic compression and expansion of air or other gas. At different temperature levels all heat is transferred to and from the gas (working fluid) through the engine wall to produce energy. It runs at a 60% efficiency rate and is an extremely quiet hot air engine.

Tom then showed us a simple barbecue lighter but explained in simplistic terms how it worked which is really something I had never thought of before. It has small rectangular cortz crystals that when squeezed to produce the flame, gets high voltage, also known as the Peizo-electric-effect. This same effect happens in lawnmowers and radio transmitters. We also looked at a solar powered engine where the solar cells convert light into electricity through traction and the repulsion of magnets.

The most interesting display to me was the wireless transfer of energy that he showed us. By turning on an electric generator, the tessler coils at the top showed visible purple sparks. Tom took a long wand filled with neon and mercury vapor that lit up half blue and half pink when the electricity was transferred through the air. Old school medical devices from the 1800s were also shown to us which really did not help anyone at all, and other fun devices like electric fly swatters with a high voltage osculation was also displayed.

Overall, Tom Vale used very interesting visual aids and one of a kind humor in his presentation that drew in the audience and helped me learn about the different kinds of engines and energy generators we can use to promote alternative energy for our future generations.

 

Generator Lab

 

 

In this lab we used a magnet generated flashlight, LabView software, and physical number of shakes of the flashlight to measure the voltage increase among shakes. The premise and basis for this experiment is Faraday’s Law where the move the magnet in the flashlight is moved back and forth between the wire coils, electrical currents are generated which coincides with the law of induction. The cut through the line of fluxuation is the current and in this we are looking for the  change in B over the change in T.

Experimental Process:

1. Measure the flashlight voltage with no shaking for 30 seconds

2. Start to shake flashlight slowly for another 30 seconds

3. Faster than before (30 s)

4. Faster again (30 s)

5. Finally as fast as you can possibly shake the flashlight (30 s)

Pay attention to the voltage difference in each trial and record it into the Excel spreadsheet. After you gather the voltage data you need to find the sum of squares of the voltages (v to the second power). Sum of squares is the mathematical approach to find the dispersion of data points in a regression. Here we wanted to find the dispersion of voltage points at each shake level. The sum of squares helps to find the function that varies the least from the data and that is why we chose to graph those data points.

After conducting this I saw that the more energy exerted in the shaking and the higher the number of shakes, the more voltage that was generated. In the below link you will see a breakdown of the numerical data, as well as a chart to depict the sum of squares at each shake level.

Generator Lab Excel Sheet

 

MIT Nuclear Reactor

control room with operator                                                        outside picture of the MIT reactor                                 view of the reactor from above

 

 

On Monday, our class was lucky enough to be able to tour a research nuclear reactor on the MIT campus. I was surprised at how simplistic the building was when I first arrived, but what went on inside, was anything from simple. When we first got there safety was of the upmost concern and we were given radioactive trackers to make sure that their levels did not increase after we left the tour of the plant. Our tour guide started off by explaining how the reactor functioned.
The core of the reactor has fuel in the center and is the size of a 30 gallon trash can. It is 1 of 2 in the country that is HEU based but is going to be changing over to LEU soon. There are 2200 gallons of water pumping through every minute to cool the fission and lower the energy taking place. There are also D20 reflectors that scatter and bounce  back into the core. 6 boron/stainless sleel blades expose the fuel to the reactor around it. With this, borons absurb the neutrons formulated and remove the harmful chemicals within. If the reactor were to reach the super critical point, power would be greatly increased to stable the fission.
The reactor is generally kept at 50 degrees Celcius and the captured heat goes to the secondary system into the cooling towers with large fans and evaporation equipment are used to where the temperature drops to 30 Celcius.
The whole point of this specific MIT reactor is to make radiation for research purposes. From a saftey precaution, it is designed to keep water from boiling around the aluminum and is inspected every 6 months to make sure that the core is not blocked. Design flaws do happen which was the case with Fukushima where there wasa decay in chain energy being produced and the backup reactors were destroyed by the Tsunmai ocean wall. Here at MIT they have natural convection valves so  that water can not get past is and as horrific as Fukushima was, it was a learning and research case for reactors all over the world in the hopes that a disaster of this nature will not happen again. Since the MIT reactor looks to research there is a tube in the core made of an alumninum dummy and they can project how the material will be damaged with the release of neutron damage.
There is a misconception between radiation and contamination which our tour guide explained. Radiation is the energy coming off of the radioactive particle, and the particle is the contamination. The particle can be looked at as metaphorical radioactive “weeds” and radiation is the grass that it is grown on and the contamination is not wanted. To keep all systems acting appropriately, refueling occurs within the reactor. Surrounding the core, there is static and neutrons that change over time so refueling occurs every 2 to 3 months to shuffle the fuel. To asist is absurbing neutrons, cadmium is used.
From a safety standpoint, steel and lead is used to protect reactor workers from radiation contamination and they are allowed 5 REM of contamination a year. Various research projects are being utilized at the MIT reactor and one of them previously was brain cancer research where patients who were terminally ill were given doses of radiation from the neutron beam and showcased 6-8months more life in many cases.  Prostate cancer was also tested on and gold was placed in the body to irradiate tumors in the specific area and the decay was about a 2.5 day half life.
Overall I got an amazing impression for those individuals who work at the reactor. Safety was the top of the list and I got to step on a radiation contamination detector which not many people can say, and saw that the depths of scientific discovery are endless and we owe these people great thanks for providing us with energy sources and even possibly curing diseases in the future.

source: tour guide MIT representative

Solar Cell Lab

 

In the solar cell lab we looked at the measuring the correlation of voltage difference between the front and back of a solar cell. We took a ruler at and measured the voltage produced on LabView software at various distances; first starting with zero distance. The light intensity by defintion is the measure of energy of light and voltage is the amount of energy per charge required to move the charge around a circuit. The higher the intensity, the more photons that are generated which equals greater current flow and voltage. We found that this was conclusive in our experiement because the further away we measured the light from the solar cell, the lower the voltage was and the less intense the light was as well.We also put different colors of film across the solar cell light (blue, pink, and teal) with no distance away from the solar cell to see how the light intensity would be affected there as well. Pink had the highest light intensity with blue and finally teal following. Our results are showcased in the following Excel spreadsheet along with corresponding charts and bar graphs:

Solar Cell Lab Excel

Energy Experiment

 

 

In this energy experiment we were asked to look at mass, acceleration, battery discharge, wheel rotation, power, and force. We did this all by using a motorized pulley system where we manipulated the weights at different speeds to measure first their mass vs. acceleration. At first we put .25 kg of weight on the pulley system at power setting of 75. We then kept decreaseing the weight to .21  then finally to .15 and get the power setting steady at 75. As the acceleration increased, the mass decreased. At the highest mass of .25kg, the speed (rpm) was 51.80 and at the lowest mass, .15kg, the speed(rpm) was 93.85 which correlates with the law perfectly correctly.

Next we looked at acceleration vs. power. We kept the mass constant at .25kg and then changed the power settings from 75 to 85 to 95. The acceleration increases as the power settings increased. When the power setting was 75, the acceleration was 31.59 rpm/s and at the highest power setting of 95, the acceleration was 59.93 rpm/s. This makes perfect sense in the fact that when speed increases the acceleration increases with that as well.

The last element we looked at was battery discharge vs. mass. We kept the mass constant at .25kg and left the power settings at 75, 85, and 95. As the power settings increased, the battery discharge increased. Starting at the power setting at 75 then the correlating discharge at 111 mv. The highest power setting at 95 had a correlating  battery discharge of 291 mv.

The following excel spreadsheet displays the three experiments that we displayed along with coordinating graphs to go along with them.

energy experiment spreadsheet with graphs

 

Pandemics

According to the FCC, a pandemic occurs when “a novel strain of a virus appears that causes readily transmissible illness or which most of the population lacks immunity”. The most common kind of pandemic is influenza that happens with little to no warning and spreads geographically at a rapid pace that can last for 3 months.  The scariest part of pandemics is that even the leading health and disease control specialists have no way of knowing when the next pandemic will strike and what variant strain could form. Strains can form and mutate into new “knots” that no one can predict.

During pandemics up to 40% of the nation’s workforce would be absent due to precautionary/quarantine efforts.  This can cause major communication losses , where the ability to communicate via phone, text, or email could be disrupted. This could have a cataclysmic effect on our daily operations resulting in looting/stealing, highly increased crime, physical harm to others, and an anarchy infused society.

The Center for Disease Control and Prevention (CDC) has the pressure of dealing with catastrophes of this sort. On their website, they have a section providing information about pandemic flu specifically. This week they had a blog designated to the correlation between what they do, and the blockbuster movie “Contagion” that I recently saw in theaters. Heroic scientists battling imminent life and death situations are not just part of a movie plot; it is real life. The real stories of CDC disease detectives are just as exciting and imperative as in the movie. Contagion really created an intelligent and realistic portrayal of pandemic circumstances.

Movie star legends portrayed government response to pandemic in the movie Contagion. Controversy will always be a role when there is a major health crisis, and blogger journalist (Jude Law) dug deep into issues and secrecies of governmental decisions. He said that CDC officials and the White House were “in bed” with pharmaceutical companies while developing a vaccine to prevent again the strain of virus, and that money and power overrode the need to save millions of lives. He thought that they were holding out the truth of other natural ways of vaccination and prevention in order to gain money from pharmaceutical moguls. In the movie his blog caused a worldwide uproar, which is a definite possiibility to happen in real life in the social media and internet guided society that we live in today. Other countries in the movie looked at the United States as holding out on them when a vaccine was created and they even held a prominent scientist hostage in order to obtain vaccination from the power houses of the world.

The CDC and worldwide disease investigators are on call 24/7 in times of need. This movie was eye opening in the way that human’s primal instincts for survival really take focus. Matt Damon played a man who lost his wife and child and was immune to the disease. His sole purpose was to provide for the daughter he had left. He never reverted to crime or physicality to survive, and stayed away for the anarchy that was developing all around him. Lawrence Fishbourne who portrayed the Dr. Ellis Cheever, a disease control specialist for the CDC, is working to help the greater good, but takes care of his family and close friends first by even giving up a vaccination for himself. We all take for granted the people that are working constantly to protect us, and it goes to show that we may not trust all that the government does, but it times of disparity, they are all we have to rely on.

Figuring out the cause and next move of a pandemic and its strain is like trying to complete a puzzle where the last piece constantly changes. Scientists need live samples to test and trial and error is really the only way we have for developing prevention. At the end of the movie, Contagion, it showcased how a bat dropping infected food into a pig’s den was the start of a worldwide pandemic. It only takes one small thing, but it has enough power to keep us and our top specialists doing guesswork.

http://www.youtube.com/watch?v=4sYSyuuLk5g (Contagion trailer)

http://www.youtube.com/watch?v=d9Xu4JMd3Oo (history of pandemics; CBC news)

sources: http://www.cdcfoundation.org/content/how-cdc-saves-lives-controlling-real-global-disease-

http://transition.fcc.gov/pshs/emergency-information/pandemics.html

http://www.pandemicflu.gov/news/cdc_response_to_contagion.html

Warner Brother’s “Contagion” 2011.

Demand Response

Demand Response programs can benefit our current energy woes immensely. They give consumers the capability of trimming down our electrical usage at peak hours during the day, during times when electricity prices are high, and also during an emergency so that a blackout does not occur.

Demand in this response method is when you flip on any electrical switch in your home or business, electricity travels in an instant to that hub and gives your appliance energy. Demand response can help to decrease this demand load and apply energy conservation. Brownouts and rolling blackouts happen when electrical grids malfunction or there is a supply-demand component discrepancy. The 2003 NYC blackout alone resulted in $750 million lost in revenue.

The energy industry is looking to demand response as a hopeful applicable fix to infrastructure. The futures is in the automated direct response systems that detect demand loading problems and automatically redirect power inflow in specific areas that gets rids of the chance of overloading or power failure.

Business owners are now seeing demand response as an investment incentive where companies like PG&E allow them to limit their facility’s energy use during peak times in demand.  These incentives include peak day pricing and SmartAc applications where business owners save money on energy and also increase their sustainability in accordance to social and ethical responsibility.

Major steps in this direction can make demand response a commonality. The Demand Response and Smart Grid Coalition (DRSG) is the major trade association right now that provides smart meters and smart grid technologies that work hand in hand with demand response programs. DRSG has been educating our policymakers and government associations, as well as getting their information out to the media and financial stakeholders in the market. Associations like this can help to modernize the entire way we use electricity and promote energy conservation to a myriad of consumers.

http://science.howstuffworks.com/environmental/green-science/demand-response1.htm

http://www.pge.com/demandresponse/

http://www.drsgcoalition.org/

Wheel Rotation Experiment

During this process, I was able to find how human error correlates with the accuracy of computer systems. We had to carefully construct the robot, piece by piece which took patience and attention to detail.  After pieces started coming together, the robot assembly became easier. After the robot was assembled we had to link USB cables to the allotted areas on the robot and to the computer; the whole process went smoothly from there. We first measured the circumference of the wheel diameter in centimeters which came to 5.5 cm. We had to convert that measurement into meters so we took 5.5cm x 3.14 / 100% to get .1727 (m). We needed an accurate circumference of the wheel so that all other measurements correleated correctly. After this step we made sure that all settings were correct in LegoMindstorm. For each experiment trial that we did, we used 1 second for our time allotted for the robot to travel.

After this we started off with a power measurement of 75. At that measurement, we ourselves by using the ruler got .58 (m) whereas the LabView software got .577. In this measurement, we were very close to the computer and the margin of error was small. At the next power speed of 50, we kept the time at 1 second and phsycially measured with the ruler at .36 whereas the labview software obtained .374. This was a little bit far off from the actual measurement because our robot hit a tiny bump where the desks are together which is definitely a reason for human error. Our third trial, we manipulated the speed to 25 and we physically measured .18 and the LegoMindstorm came out with a .169 measurement.

After reviewing the error just on paper, I calculated the human error  for each segment. I took the difference of the physical measurement from the ruler and the computer calculated number over half of the sum of those two numbers. For example for the 75 speed it would be .58-.57/[ .58+.57/2 ] = 0.0051 % error which is very small for the first trial and was around the same for the other amounts which showcases that there is human error present and that technology can give a more precise answer, but we can get close to that as well.

Fukushima blog:

Fukushima nuclear disaster blog

After the Tohoku earthquake and tsunami in March of 2011, the Fukushima nuclear power plant endured a series of equipment failures, meltdowns, and the release of harmful radioactive materials. It is the largest of the 2011 Japanese nuclear accidents since the Chernobyl disaster over 25 years ago. In the accident, all external power sources had been lost which reacted in the cooling water to all 3 reactors in the plant failing. Hydrogen started being generated because of the chemical reactions occurring between fueling rods and the rising flood waters which caused massive explosions to the reactor buildings themselves and left a disarray of damage. The International Nuclear Event Scale (INES) put this disaster at a 7, which is the highest rank.

Dealing with the tainted water after this catastrophe was and is a huge struggle. Immediately following the event, the first act was to put water into the reactors and nuclear fuel pools to cool down the incredibly hot fuel.  TEPCO went through several failed plans of action in dealing with this disaster. They tried to construct a purification system that would separate the radioactive materials from the contaminated water so that they could use it to cool down the reactors. Leaks in the hoses used to transfer the water and malfunctions in the purification process slowed down this entire process and over 30 mishaps have occurred up until August in recovery efforts. Lack of preparation is a huge constitute to this horrific event, and is an awful lesson to be learned for the future.

A professor, Yoichi Enokida, at Nagoya University states that the “lack of objective views of the operation rate of the newly adopted nuclear waste removal system has only contributed to everyone’s rising distrust of nuclear power as a way of generating electricity.” From this disaster up to 1/7 of Fukushima may be polluted, and further implications will not be known until they show their disastrous colors in the future.

Since the six month ordeal, over 100,000 residents within 10+ miles of the plant have been evacuated. Rescue workers are exhausting their resources to try and recover the cloud of radio activity that swept over the surrounding areas. Radiation levels in the immediate area have diminished but not a substantial amount. Animals and cattle are roaming wild suffering from the elements, and Fukushima looks like a ghost town. Time may heal some of the elements, but the radioactivity seeping into the soil proves to be a detrimental problem for generations to come.

Video of the blast: http://www.youtube.com/watch?v=D7crIPPhmVI

Explanation of the hydrogen explosion:  http://www.youtube.com/watch?v=Kgo24tTyC_c

Image explaining devastation from tsunami: http://images.scribblelive.com/2011/3/17/2b61cf86-26b7-498c-96aa-e5ad2a684d0a_500.gif

Image: http://www.google.com/imgres?q=fukushima+explosion&hl=en&sa=X&gbv=2&tbas=0&biw=1600&bih=799&tbm=isch&tbnid=c3xfyTk9N7UjPM:&imgrefurl=http://www.sovereignindependent.com/%3Fp%3D15831&docid=sJe0FJdWPyGt9M&w=284&h=177&ei=oStyTqCBFILt0gGW45jzCQ&zoom=1&iact=hc&vpx=578&vpy=162&dur=3010&hovh=141&hovw=227&tx=142&ty=78&page=1&tbnh=107&tbnw=179&start=0&ndsp=36&ved=1t:429,r:2,s:0

http://mdn.mainichi.jp/mdnnews/news/20110910p2a00m0na008000c.html (source)