By Stania
Will the bag pop?
What do you think will happen if I stick all these pencils through this bag full of water? Will the bag pop?
- HOW DOES IT WORK?
The zipper-lock plastic bag is made out of a polymer called low-density polyethylene (LDPE). LDPE is used all over the world for packaging because it is low in cost, lightweight, durable, a barrier to moisture, and very flexible. The bag’s flexible property helps to form a temporary seal against the edge of the pencil so it can go through properly without breaking the bag.
- WHAT I LEARNED FROM THIS EXPERIMENT
The force needs to be (pencil) perpendicular to the surface (zip-lock bag). How to apply Pascal's principle and formula to my experiment. How force and area will equal to your pressure. Why pressure has to be equal everywhere to get accurate results.
(By Rachel)
Floating Needle
A needle has a higher density than water. Normally, it falls directly to the bottom of the water. But when the needle is put into the water horizontally with caution it can float due to surface tension. The water keeps its round shape because there are no water molecules outside the surface to balance this inward pull. Putting the needle horizontally to the surface of the water has a larger contact area and less pressure is exerted on the water surface. (Breanna)
Velocity in Uniform Motion
The graph was done in Excel 2010. Notice that all the point are exactly aligned, which means that the air track was perfectly leveled.
Metric System - 150 Years in the United States
The metric system was officially recognized as a system of measurement that can be used in the United States on July 28, 1866
Source: 39t Congress, Chapter 301
"Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That from and after the passage of this act it shall be lawful throughout the United States of America to employ the weights and measures of the metric system; and no contract or dealing, or pleading in any court, shall be deemed invalid or liable to objection because the weights or measures expressed or referred to therein are weights or measures of the metric system"
Image distance vs. object distance; f = 25 cm
Data collected by Melissa and Naomi
1/x + 1/y = 1/25 x = 25 y = 25
Can We Use Lightning as a Source of Energy?
Storing the energy from lightning sounds like a
great solution to our energy crisis if it could be harnessed. Lightning bolts carry from 5 kA to 200 kA and
voltages vary from 40 kV to 120 kV. So on an average, a bolt generates 100 kA
and 100 kV. There are an average of 1.4
billion lightning strikes a year, but only ¼ of those strikes are ground strikes. That means ¾ of the strikes are cloud to
cloud strikes and cannot be harnessed.
That being said, there are still 350 million lightning strikes, or still
about 490,000,000,000 kWh that we should be able to capture, transfer and
store. Sounds like that would provide plenty of energy to power the world!
The problem is we do not have that technology
in electrical energy storage, at this time in history, to harness the
power. But even if we did, that only boils
down to providing enough electricity to power the world for 9 days. We would have to build some kind of device big
enough to get hit by enough lightning strikes to supply the desired energy.
There would have to be towers erected about the height of the World Trade
Center. To capture every lightning strike these very tall towers would have to
be erected a mile apart in grid formation everywhere covering the entire
globe! That would be one tower for the
200,000,000 square miles of the surface of the earth! The equipment needed to capture this much electrical
energy in a strike would have be heavy conduction rods with ultra-heavy duty electrical
circuits and storage super-capacitors so that it would be able to capture any
of that power in that time period. On
top of that, there is the problem of financing such a massive project! The cost for each tower and electrical
circuitry storage would be around $500,000. That is about $100 Trillion for the
land equipment. Then there would have to be flotation towers for the oceans.
Plus, the installation costs and regular maintenance, and the wire grid
connecting all the towers together, making it probably more money than we have
in this world! Add to that the
impossibility for the entire world to agree on this concept and project… or
agree on anything globally!
Compare all that with
the fact that one hour of sunlight has the same amount of energy that we use in
a year! We have much more power available from the sun and we only need our
rooftops to accumulate all we need. Especially with the advances and improvements
being made with solar panel efficiency. Another major challenge to harvest
energy from lightning is the impossibility of predicting when and where thunderstorms
will occur. Statics show that lightning strikes on an average of once in 10 years
to the same general place. Even during a
storm, it would be difficult to determine where exactly lightning will strike,
but the sun shines continually!
(by Tim)
__________
References:
The Future of Electricity
Years ago, I was a pupil in the elementary school. At that time, the only electric thing that existed in my family was light bulbs. Those light bulbs were very similar to the one Tomas Edition had invented one hundred years ago. I thought those light bulbs were very useful to my family, but the television that was in my neighbor’s house was just an entertaining tool. Without light bulbs, we would light candles to bring us light in the house, and we could still live well. At the present, however, like many people, I totally have changed my point of view to the significance of the electricity, and regard electricity as a daily life necessity. Except light bulbs, people need many other kinds of equipment requiring electricity, such as: phones, computers, refrigerators, air-conditions and so on. Therefore, currently, electricity has already become a part of most people’s life. According to this fast pace of development, humans will relay on electricity much more in the future. What does the future electricity look like? Two significant parts I want to mention in this paper are electricity generation and electricity transmission.
In this modern technology era, electricity demand is constantly increasing with individuals and in society. There are different points of views toward the future of generating electricity. On the one hand, a majority of voices are positive about developing more renewable energies (solar, wind, hydro, geothermal, biomass, etc.) in the near future (Islam, Hasanuzzaman, Rahim, Nahar, & Hosenuzzaman, 2014). For instance, M. A. Islam and his companions stated that renewable energy will ultimately fulfill 80% of total energy requirement in the end of this century even though natural gas will temporary play a main role in the coming two or three decades (Islam et al., 2014). Apparently coal, one of the fossil fuels will gradually decrease its role in the future due to its excessive carbon emissions. In addition, David Biello stated as well that renewable energy and natural gas may become main sources for electricity in the near future in the United States (Biello, 2010). On the other hand, renewable energy could not satisfy all of the future’s energy needs. Applying nuclear energy is a very debatable issue from decades ago until now. According to Alan McDonald (2008), nuclear energy will have a very different future in each particular country around the world regarding its own experience and perspective to nuclear power. In general, Asian countries, especially China and India, tend to build more nuclear power plants now and will continue in the future, since they need electricity in large quantities. In comparison, some developed European countries would decrease the use of nuclear power plants, and instead they will lay special stress on developing renewable energies. Obviously, each nation has its own plan to satisfy its particular electric demand.
Electricity transmission is another key element to the future of electricity. The current electricity transmission may waste electricity and have some security problems. However, smart grid systems are able to provide a more efficient transmission and cut down the potential safety hazards, such as environmental pollution due to the process of the electricity (Islam et al., 2014). Moreover, a smart gird is able to achieve more accurate date and analyses, more flexible managemen and mutual communication with customers. In the article, Islam and his partner writers suggested applying the smart grid system to the sustainable energy generation, and it will open a new page to meet both social and environmental needs in the future.
To conclude, there are more than one options to optimize the future of electricity. It could be choosing a better power resource, sustainable energy, or improving electric grid efficiency, which will be a good choice. Meanwhile, when we are trying to get power, we should be concerned about our planet, where it is not only our home but also our next generations’ living place. Besides the ideas I have mentioned above, I believe that humans have the ability to solve our electricity problems and ultimately meet our future needs. It even could be something else to substitute electricity at some future date.
(by XN)
_________________
References:
- Biello, D. (2010). Where will the U.S. get its electricity in 2034? Scientfic American. http://www.scientificamerican.com/article/where-will-the-us-get-its-electricity-in-future/#
- Islam, M. A., Hasanuzzaman, M., Rahim, N. A., Nahar, A. and Hosenuzzaman, M., “Global renewable energy-based electricity generation and smart grid system for energy security,” The Scientific World Journal, vol. 2014, Article ID 197136. http://dx.doi.org/10.1155/2014/197136
- McDonald, A. (2008). World nuclear position. https://www.iaea.org/sites/default/files/49204734548_zt.pdf
- REN21. (2012). “Renewables 2012,” Global Status Report.
- REO. (2012). “Renewable energy outlook,” World Energy Outlook. http://www.worldenergyoutlook.org/media/weowebsite/2012/WEO2012_Renewables.pdf.
Kirchhoff's Loops and Junctions
The blue loop: V1 + V5 + V3 = 0
The purple loop: V2 + V5 + V4 = 0
The green loop: V1 + V2 + V4 + V3 = 0
The orange junction: I1 + I2 + I5 = 0
The green junction: I3 + I4 + I5 = 0
Resistors in series
There are three resistors in series: 1st 330 ohm, 2nd 100 ohm, and 3rd 1,000 ohm.
The first two resistors add to 430 ohm (the reading: 428 ohm, 0.5% difference).
The second and the third one add to 1100 ohm (the reading: 1097 ohm, 0.3% difference).
All three resistors add to 1430 ohm (the reading: 1424 ohm, 0.4% difference).
Resistors combined in series and parallel
Two 10 ohm resistors in parallel are combined with the third 10 ohm resistor is series. The calculated total resistance of the combination is 15 ohm (two 10 ohm resistors in parallel = 5 ohm, plus 10 ohm in series). The measured total resistance is 14.8 ohm and 15.2 ohm; in both cases the measurement error is about 1%.
Resistors in parallel
There are 10 ohm resistors in parallel. The equivalent resistance for two 10 ohm resistors in parallel is 5 ohm. The measured value, as shown in the picture, is 4.98 ohm (percent error of 4%).
The equivalent resistance for three 10 ohm resistors is 3.3 ohm. The measured value (see the photograph) is 3.5 ohm (percent error of 5%).
Resistors in series
There are three 10 ohm resistors connected in series.
The equivalent resistance of two 10 ohm resistors is 10 ohm + 10 ohm = 20 ohm. The first measurement error is 0.5%, while the second one shows the exact expected value.
The equivalent resistance of three ohm resistors is 10 ohm + 10 ohm + 10 ohm = 30 ohm. The measured resistance of these three resistors is 29.8 ohm; the percent error 0.67%
Alexander Hamilton and the establishment of industry
History proves that a connection of science and business fuels innovation, development, thereby strengthens economy. Alexander Hamilton (1755 - 1804), the United States first Secretary of Treasury, was a visionary politician who greatly supported the establishment of industry in the States.
The city of Paterson was one of the first industrial cities in the United States. The manufacturers were using the energy of the Great Falls. Before electrical transmission lines were invented, transporting energy was a challenging task. How would one transport the energy of the waterfalls to the factories without electricity? The answer to that question required an open mind, creativity, courage, broad knowledge, the ability to convince others to accept an innovative idea, and perseverance. The combination of all these qualities was a foundation of the industrialization of the city of Paterson, and the phenomenal growth of the economy.
Alexander Hamilton statue, Great Falls National Historical Park
(photo by Anthony)
An image of the Sun
Thanks to Victor Davies, a member of the Amateur Astronomers Association of Princeton, this summer we had an opportunity to observe the Sun through a telescope (photos: above by Karen and below by Anthony)
Observing the Sun (2)
Solar-projection method
Do not watch the Sun directly through the telescope! Instead, observe it on a paper screen.
How Do Other Foreign Countries Deal the Daily Waste?
It is always beneficial to know how other foreign countries deal with the daily waste of materials differently. Probably individuals can get some insights, which could help them in promoting knowledge, skills and increasing the possibilities of how to reuse wasted things and to save more energy for the future. As most people know, in the education field, educators and students need a great amount and a variety of materials to make their teaching and learning more interesting and more creative.
Canada is a good example of providing those used materials to teachers, students, and artists by the Artsjuncktion. According to Garnet (2014), the author of the article, “Recycling Material Culture”, “The Artsjunktion is a free service located in the downtown core of Toronto that accepts, sorts, and distributes all forms of material culture, providing an environmentally friendly source for art materials” (p. 2). Actually, by the service of the Artsjunkson, schools saved the budgets of purchasing educational supplies for the art class (2014), and students learned how to save the resource by creatively using it. However, the Artsjunkson cannot handle all waste that people produce from everyday life.
Sweden imports waste from European-neighbors as fuel to give a rich supply to the country-wide energy needs (The Swedish Recycling Revelation, 2015). Apparently, it is both a solution of saving energy and reducing waste to pollute the environment. Therefore, understanding disposing trash from a global view, individuals could really get a wider thought toward solving current environmental problems that are challenging humans.
Naomi (XN)
_________
References
Garnet, D. (2014). Recycling material culture: Environmentalism, free art supplies, and Artsjunktion. International Journal of Education & the Arts, 15(2). Retrieved from http://www.ijea.org/v15n2/.
The Swedish Recycling Revelation. (2015). Retrieved June 9, 2016, from Swedish Institute: https://sweden.se/nature/the-swedish-recycling-revolution/
Reduce, Reuse, and Recycle
The question that many people may find themselves asking is why bother taking the time to recycle. In this article, we will discuss the true meaning of recycling such as the how’s, whys, where the recycling goes and lastly how does the term “recycling” correlate to physics. Recycling is the means of gathering items that can be thrown away but used to create new goods. It is an essential element in progressing the environment and saving natural resources. Some of the ways to promote recycling are to recycle at schools and businesses by recycling items into a specific container, recycle empty ink cartridges and cash for cans are just a few to mention.
Recycling would cut down on the volume of the remains that go to disposal sites and the remainder of landfills would last longer. The question in mind here is “why bother to recycle”. For starters, glass is made from all natural resources which can be reused for new glass. It can also replace about 95% of the raw materials that is required to create new glass. For example, recycling just 10 glass containers can save an adequate amount of energy to have a tv run for 2 hours. For every 165 gallons of gas and the vitality to control a typical household is comparable to a ton of recycled paper; one ton also saves about 17 trees. Also, according to the EPA, recycling paper causes 35% less water pollution and 74% less air pollution than making paper from raw materials. Overall everyone can make a difference, let's use the 3 R’s- Reduce, Reuse, and Recycle.
Maria
Laser ray captured between two glass surfaces
Photo 1. The laser ray is captured between two glass surfaces.
Picture 2. The incident, reflected, and refracted rays are sketched. Notice that the two refracted rays at the left are parallel (the same angle of refraction!)
Picture 3. White A at the right side indicated an incident angle; the blue A shows a reflected one. All angles A are equal. B in lower right corner is an angle of refraction, other B-angles are both incident and reflection angles. All angles B are equal.
Subscribe to:
Posts (Atom)