In class we constructed the NXT System and gave our little robot directions to move forward. We repeated this process three times, each time using different power on the wheels. We measured the distance the robot moved for each power usage and then compared to the actual distance it moved that we got from the NXT program. Also, we recorded the number of turns the wheels did and the time for each power usage.
Results:
From the table we can get the results we acquired for the experiments we carried out.
How are degrees and number of turns linked?
We know that each turn is 360 degrees, which means that the number of turns represents how many times the wheels have turned 360 degrees.
How is the distance related to the number of turns?
The distance is directly proportional to the number of turns of the wheels;the more(or less) the turns, the more(or less) will be the distance covered.
In fact by knowing this we can even find a formula for the two variables. That formula is Distance=(1.8*10^-4)*numberof turns
Recorded Distance Vs Actual Distance:
From the table we can clearly see that the distance we recorded was not the same as the actual distance. From our results we can calculate the percentage error that our measurements had. When the power was set at 75, the percentage error was 4.48%. When the power was 85 the percentage error was 2.72%. Finally, when the power was set at 100 the percentage error was 3.48%. We can understand that our measurements were off by approximately 3.5% on average from the actual measurements. The cause for the discrepancy we recorded is three-fold. When the car was moving, it would move slightly after stopping due to inertia. As a result, we had to estimate the spot it stopped at and apparently our estimates were not 100% accurate. The other factor that played a role in the discrepancies was that we were using a ruler, which has a set limit of accuracy and that limited our estimates further. Finally, the fact that the wheels were not turning at the same rate(the table shows that the degrees varied with each wheel) indicates that the car was not moving in a straight line. Since we were recording the straight line that the car moved in, we did not get the actual distance, which in this case was a sort of a hypotenuse.(while our line was the line opposite the hypotenuse that is smaller than the hypotenuse.) This fact also explains why our results were always less than the actual distance. If you are finding it hard to visualize the problem then the amazingly cool represantation that i created using paint might help.
Ultimately, it was another fun class that taught us again that computers are better than us.
Throughout the day we constantly use electricity. From turning on the lights to using the microwave oven, we continuously consume electricity. It is understable that during some periods our demand for electricity increases. For instance, in the summer we usually consume more electricity due to the fact that the temperature is high and we use air conditioners all day. These periods that electricity consumption reaches a peak are called peak usage times. The past years though our demand for electricity has grown larger and according to the Energy Information Administration it will increase by 40% by 2030. In order to limit our demand some programs called Demand Response programs have been created. These programs allow the users(us) to voluntarily decrease energy consumption during times that electricity cost is high(peak usage times). As a result of this we can both save money and electricity.
Implications:
The United States release approximately 150 million tons of carbon dioxide in the atmosphere for electricity generating purposes(source U.S. Department of Energy). By using demand response programs, the amount of energy needed to be produced will be less, hence the release of pollutants and greenhouse gasses will reduce as well.
”In a yearlong, small-scale study in homes on the Olympic Peninsula in Washington, the Department of Energy (DOE) found that when consumers were equipped with smart electric meters, thermostats, water heaters and dryers, they reduced their energy usage and associated costs — on average, participants saved 10 percent on their electricity bills, and there was a 15 percent reduction in peak load usage”
The quotation above from howstuffworks.com indicates that we would use approximately 15% less energy in peak times. This means that we would avoid releasing millions of greenhouse gasses to the atmosphere if we adopted demand response programs.
Important Note:
One of the most promising concepts surrounding demand response programs is that of smart houses. In this concept houses are equipped with direct response energy, which is a system that constantly regulates the amount of energy used in various time-periods. For instance, direct response will decide to produce less energy during peak hours(when the price of electricity is high) and turn off appliances such as the thermostat, or the washing machine to save money and energy. This automatic power control used in direct response energy is used in smart houses, that use a smart grid which ” has a web of access points that could be identified and contacted. Through these contact points, the grid would automate the flow of electricity as needed, identify and isolate load problems.”(source How Stuff Works.com)
In conclusion:
It seems to be that demand response is one of the most intriguing and lucrative new technologies right now. Not only can it help us save money-a fact that is even more appreciated in our times of economic crises-but it can also help us lower our greenhouse emmisions considerably. It is a win-win situation that we must not turn our back to.
Approximately six months ago the entire world was holding its breath over one of the most dangerous contemporary disasters, the Fukushima Daichi Nuclear Plant Disaster. A massive eathquake of magnitude 9.0 richter degrees, set off a tsunami which hit the eastern coast of japan and obliterated everything in its way. Amongst of the victims of the tsunami was the Fukushima Nuclear Plant.
Basics First:
Before an analysis of the events that unfolded is provided, i think it would be better to provide a short description of how nuclear plants work in order achieve a better understanding of the problem.
The main premise of a nuclear reactor is quite similar to that of the typical coal-burning power plants, with the main idea being the heating of water into pressurized steam that drives a turbine generator. The difference between the two power plants is the way that water is heated. In a nuclear plant, water is heated through the use of nuclear fission in which one atom splits into two and releases energy. In a nuclear plant that is achieved by firing a neutron on a uranium-235 atom, which then splits into two atoms while releasing heat and gamma radiation(radiation from high-energy photons). The uranium-235 atoms are all stored in fuel rods that are assembled together and form bundles of fuel rods that emit heat. However, for us to harnest the vast amounts of energy released, a mechanism is required to control the flow of energy and limit it to desirable levels. In the nuclear plant, this mechanism is found in the use of control rods. Control rods are specifically designed rods that can absorb neutrons and help avoid overheating. These rods can be raised and lowered to absorb less and more neutrons respectively. If raised, less neutrons will be absorbed which means that more energy will be released. The controlled release of energy,then, heats water and turns it into steam, which,in turn, drives a turnine, that is connected to a generator, thus producing energy that we can use. (This is a basic description of the way nuclear power plants work. For further details, allude to http://www.popsci.com/science/article/2011-03/whats-happening-japans-nuclear-power-plants).
What Went Wrong:
In the video posted above, you will find a simpe experiment conducted by nuclear engineer Arnie Gundersen that serves as a representation of the way Fukushima’s fuel rods melted and shattered, which led to the spill of radioactive Uranium.
Implications:
The radioactive material that leaked in Japan from the Fukushima Nuclear Plant had grave implications for Japan. Firstly, the area around fukushima was evacuated immediately and Japan’s prime minister Naoto Kan was quoted saying “I can’t deny the possibility that it could be a long time before people can return to and live in regions with high radiation levels,”. Furthermore, ”in a meeting with local officials on Saturday, the government estimated it could take more than 20 years before residents could safely return to areas with current radiation readings of 200 millisieverts per year, and a decade for areas at 100 millisieverts per year.”(quotation by http://www.reuters.com/article/2011/08/27/us-japan-nuclear-uninhabitable-idUSTRE77Q17U20110827). The above information seems to verify that people that lived in or near those areas will not be able to return home for a long time.
Also, the leak of radioactive material has polluted the Pacific ocean, the soil and the air near the power plants. It was announced by Japanese authorities that in March 2011, “radioactive iodine-131 exceeding safety limits for infants had been detected at 18 water-purification plants in Tokyo and five other prefectures”, thus indicating to a water contamination in Japan. In addition to this, an article in the New York Times reported ” radiation that exceeds safety levels has been detected in tea, milk, fish, beef and other foods produced outside that zone, and as far as 200 miles from the plant.”. Furthermore, Japan also imposed a ban on beef from Fukushima and nearby prefectures, due to traces of radioactive cesium being detected in meat samples. The above facts prove that radioactive material has escaped into Japan’s natural resources, which makes them a danger for the health of Japanese people as well as Japanese fauna(a more detailed analysis of the disaster on animals and the environment can be found in an article by the Scientific American located here; http://blogs.scientificamerican.com/guest-blog/2011/03/22/impact-of-the-japan-earthquake-and-tsunami-on-animals-and-environment)/. It was reported that radioactive waste was spilled in the Pacific Ocean which additionally endangers aquatic animals nearby. A considerable effect of the above is that Japan’s credibility and commerce have been facing a steep decline, thus increasing the financial burden that Japan has to bear. It seems, therefore, that the nuclear meltdown in Fukushima, had severe implications for Japan that could turn out to be condemning for Japan’s natives, economy and ecosystem. If the results of such disasters are as unbearable as they are made out to be, why do we still invest in nuclear power, when the risks associated with it are so grave?
Reflection Time:
Japan will have to spend approximately 300 billion dollars to eradicate the results of the Fukushima nuclear plant disaster and at the same time the damage to Japan’s ecosystem cannot be undone. Apparently the risks of running a nuclear plant are high, (even when compared to the vast amounts of energy produced by nuclear plants) and Japan’s disaster underlined the gravity of the situation, which seems to have taught us a lesson. After, the nuclear disaster, Prime Minister Naoto Kan declared that he wanted to diminish the country’s dependence on nuclear energy, increase safety features and invest in safer alternative sources for energy. His example, has been followed by people all around the world who in light of the disaster, have decided either to reduce nuclear energy dependence or increase safety measures in nuclear plants. Such countries include Germany, Italy, Switzerland, France, India, etc. An elaborate analysis on the effect of the Fukushima disaster on the nuclear industry is provided in the article below; http://spectrum.ieee.org/tech-talk/energy/nuclear/fukushimas-impact-on-nuclear-power. In conclusion, it seems that Japan has just faced one of the worst disasters in recent history. However, what is left for us now, is to pick up our pieces and think carefully about the consequences of our actions. Nuclear power plants need to be safer before they can be regarded as the future of energy and that can be achieved by further research and investment on them. Noone wants to witness a repeat of what happened in Japan, so maybe it is time to learn from our mistakes, and be patient with this subject.
