. ~ EXAM 3 NOVEMBER 17, PHSX 2004 Dr. Adrian Melott 111 EXAM Instructions : I. Read both sides of this cover sheet. 2. All marks on the answer sheet should be in #2 black lead pencil. 3. Do not start doing any problems before filling out the identification section on the answer sheet. Be sure to fill in the dots below your name and ID number . 4. Having more than one answer sheet in your possession(or in your general vicinity is forbidden and will be treated as academic misconduct.) 5. Do all your scratch work on the question sheets. The question sheetswill not be collected. They will not be used in any way in detemlining your grade. 6. A correct answer will be awarded 1 point. No answer or an incorrect answer to a question will be awarded 0 poi;nts. An educated guessis, therefore, worthwhile if you are not sure of your answer. 7. Your answer sheet and question sheet should lie flat on your desk during the test. 8. Once you leave your seat to hand in your exam, nothing further, not even your NAME or ID may be written on your answer sheet. 9. All rules described on the original course infomlation sheet apply to this exam. 10. Each question has only one correct answer. Exam NameNote: Questions 24 and 25 are extra credit. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) According to Kepler's laws, the paths of planets about the sun are ~ A) parabolas. B) circles. C) straight lines. ~ E) none of these. 2) According to Newton, doubling the distance between two interacting objects A) divides by 2 the gravitational force between them. force between them. the gravitational Iorce between tnem. E) has nO effect 3) If your mass, the mass of the Earth, and the mass of everything in the solar now, yet everything stayed the same size, your weight on Earth would system were twice as much " as it is A) be the same. )4. double. \CYtuadruple. D) be eight times as much as now. E) none of these. 4) The planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. This is because A) your mass is 100 times less on Jupiter. ~upiter &piter's is significantly farther from the sun. radius is 10 times the Earth's radius. D) you are 100times more weightless there. E) none of these. 5) There are no tides to be seenin the community swimming pool because <! A) gravitation on the small mass of water is negligibly small. "t is shallow compared to the ocean. C) 1 parts of it are practically the same distance from the moon. they are masked by the much stronger pull of Earth gravity. E) but there are, at nightime. 6) A bullet is shot at 1000 mi s horizontally bullet land ? from a tower 20m tall. How far away on a horizontal plane will the A) 1000 m @oom C) 1500 m D) 20,000 m (20 kIn) E) 500 m 1 7) Which two basically describe the same thing in different language? A) Dark energy and dark matter B) Dark matter and the expansion of the Universe C) Dark energy and the cosmic microwave background @ark energy and Einstein's cosmological constant E) Dark matter and redshift 8) Which location or country is the primary starting point for the exploration in the film Cosmic Voyage {where the lm hoop was shown)? GJ)enice, Italy B) Four Comers area,United States C) Red Square,Russia D) A yers Rock, Australia E) somewhere in the SaharaDesert, Mali, Africa 9) What were the people trying to understand who asked Feynman "Is Electricity Fire?" A) Alternate methods of generating energy. B) Ways of conserving energy in household lighting. -the threat of household fires from electricity . the quantum theory of light. 10) Which of the following expands most when the temperature is lowered? Equal volumes of A) iron. B)wood. ~elium. ~ater at 4 degreesC. E) None expands when the temperature is lowered. 11) Room temperature on the Kelvin scale is about A) 100 K. B)200K. ~OOK. ~OOK. E) more than 400 K. 12) The white-hot sparks that strike your skin from a 4th-of-July-type sparkler don't harm you because A) they have a low temperature. low. molecule is high, but little energy is transferred becauseof the few molecules in the spark. thermal conductivity E) white-hot is too far above the range of thermal damage for skin 2 ~ ~ 13) the specific heat of iron is around 0.1, and that of water is around 1.0.Place a kilogram block of iron at 40 ~ e reesC into a kilogram of water at 20 degreesC and the final temperature of the two becomes A) ss than 30 degreesC. ) at or about 30 degreesC. C) more than 30 degreesC. D) it cannot be determined unless the massesare given. E) it cannot be determined unless the temperature are given in degreesKelvin. Figure 19-A ... - ... ~ -_/ - "--" .., - -- 14) Radio waves travel at the speed of light, 300,000kIn/ s. The wavelength of a radio wave received at 100 megahertz is ~ A) 0.3 m. ~.:).O m. C) 30 m. D) 300 m. E) none of these. 15) Two chargesseparated by one meter exert I-N forces on each other. If the magnitude of each charge is doubled, the force on each charge is A)IN. B)2N. @N. D)8N. E) none of these. 16) If a steady magnetic field exerts a force on a moving charge, that force is directed A) opposite the motion. in the direction of the motion. ~ ) right angles to the direction of the motion. alternately in the direction then away from the direction of motion. E) a magnetic field has zero force on any electric charge! 17) A device that transfo~ctrical A) generator. \7'otor. energy to mechanical energy is a C) transformer. 18) Which of these electromagnetic waves has the shortest wavelength? A) radio waves Ainfrared waves l.:7-rays D) ultraviolet waves E) light waves 3 D) magnet. E) none of these. ~I ~ . . ~ ~ ) glasses. + reading '. glasses. C) both. D) neither. E) it cannot be determined. 20) The soUIce of all electromagnetic waves is A) heat. B) magnetic fields. ~lectric fields. ~ibrating charges. E) none of these. 21) Different colors of light correspond to different light A) velocities. B) intensities. C) polarities. G)requencieSo E) none of these 22) The sky is blue becauseair molecules in the sky act as tiny ~ ". rors which reflect only blue light. B) sonators which scatter blue light. sourcesof white light. D) prisms. E) none of these. 23) The worst thing you can do for the health of a green-leafed plant is to illuminate it with only D) all are equally naughty. E) none of these. 24) In his article "Blinded by Science",C. Mooney was primarily concerned with A) People'stendency to uncritically accept the claims of science B) The government's tendency to overfund someresearchareas (with obvious practical applications) at the expenseof others which might offer bigger long-term returns C) The prevalence of laboratory accidents which leave technicians blinded in one or both eyes lij1'"e tendency of journalists to introduce a kind of bogus "balance" that leaves people confused about what qs.~he generally acceptedview of scientists E) Scientists inability to seebeyond the confines of their own narrow researcharea. 4 \ 25) J;ll{ most recent new test of General Relativity was accomplished by ~ouncing laser signals off a pair of satellites \ B) receiving gravity waves from a black hole C) making black holes in the laboratory D) measuring the speed of moving clocks E) measuring the orbit of the planet Mercury 5