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5 question totalquestion 14.1.114.2.114.2.215.1.115.1.2................................ lecture13_16s20_allq13_14.pdf Unformatted Attachment Preview Question LQ13.1.1: Nuclear Physics u Which statement about Nuclear Physics is false? A) Nuclei are held together by the strong interaction. B) The strong interaction is shorter range than the Electromagnetic interaction. C) Nuclei are composed of protons and neutrons. D)Nuclear physics is complicated because protons and neutrons are not point particles. E) None of the above are false. 0 Question LQ13.1.2: Band of Stability u Which statement about the band of stable nuclei is false? A) N≈Z because the strong interaction between protons and neutrons is the same. B) N≥Z because of the EM repulsion between protons. C) The band of stability is very narrow because neutrons can decay into protons and vice versa. D) The band of stability is partly determined by which atoms can bind into molecules. E) None of the above. 1 Question LQ13.2.1: Nuclear Shell Model u Which statement about the nuclear shell model is false? A) Nuclei with a closed shell have relatively larger abundances. B) The nuclear shell model works because many neutrons can be in the same state. C) Nuclei with a closed shell of n or p are more tightly bound. D) Closed shells of n or p are spherically symmetric and thus easier to understand. E)None of the above. 2 Problem LQ13.2.2: Half Life u If the probability of a radioactive isotope to decay in one second is 10-14, what is the half life of that isotope? A) 1014 s. B) 6.93 X 1013 s. C) 1.44 X 1014 s. D) There is not enough information to determine. E) None of the above. 3 Question LQ13.2.3: Natural Radioactivity u Natural radioactive elements are found on the earth because: A) Heavy isotopes produced in supernovae have very long lifetimes so they are still present on earth. B) Cosmic rays produce radioactive isotopes continuously. C) Decay products of long lived heavy isotopes are produced continuously. D) All of the above. E) None of the above. 4 Question LQ14.1.1: u What nuclear magnetic moment should we get for 12C? (in nuclear magnetons) 5 Question LQ14.2.1: Power from Fission Reactors u Which statement about the future of fission rectors is True?: A) Fission reactors are certainly too unsafe to use for future power generation. B) There is no need for fission reactors in an era of cheap power from wind and solar. C) Fission reactors are vital to satisfy our future power needs. D) The current fission reactors should be copied and used for stable power in the future. E) None of the above. 6 Question LQ14.2.2: u u u u u u u We have not studied it here, but the earth’s climate is warming due primarily to green-house gas emission by humans. While we continue to understand more details of the climate, past models have be pretty accurate in predicting changes in the earth’s climate. This causes neat from the sun to stay with the earth and thus causes the earth to warm up. Most of the heat goes into the ocean, warming it up. Because weather etc. causes a variation in relative warmth of the ocean versus the atmosphere, there are fluctuations in the rate of warming of the air. Only recently have we made good worldwide measurements of the ocean temperature (versus depth). The new data are quite consistent with the expected heat flow to earth. There are some good things about CO2. It helps crops grow and probably need less water. It keeps us from going back into heavy glaciation with miles of ice covering Canada and much of the northern US for example. But we now certainly have too much and the rate of increase seems to be growing. CO2 does not leave the atmosphere very quickly. Without human intervention to remove it, the content would remain about the same for the order of a millennium and the earth would continue to warm in that time, moving more heat into the ocean. Obviously we have to stop this. It is quite possible that the consequences will be worse than expected. Most scientists think we have to go to zero CO2 emissions in about the next 20 years, starting to decrease emissions now. Which of these things should we NOT do immediately to stop the increase of CO2 in the atmosphere? A) Completely Electrify our cars, trucks, trains and busses. B) Build solar and wind (electric) power as fast as is practical. C) Preserve the tropical rainforest and even grow more in places we have already burned. D) Stop all fracking to extract fossil fuels. E) Reduce our consumption of meat to reduce large green-house emissions for agriculture. My Advice to UCSD Students Don’t buy land within 10 m of sea level. 7 Question LQ15.1.1: Matter Particles u Which A) There are three generations of spin 1/2 matter particles. B) Electrons are elementary pointlike particles. statement about the elementary particles of C) Quarks are elementary pointlike particles. matter is D) The first generation of matter particles false. accounts for all stable matter. E) None of the above. 8 Question LQ15.1.2: 1, 2, 3 Interactions u Which statement about the EM, Weak and Strong interactions is false? A) The three interactions are all gauge theories. B) All three theories have vector fields. C) The strong interactions had been hard to understand because of quark confinement. D) The weak interactions had been hard to understand because of spontaneous symmetry breaking. E) None of the above. 9 ... Purchase answer to see full attachment