Appendix a Glossary
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Glossary Physics (I-Introduction)
1 Glossary Physics (I-introduction) - Efficiency: The percent of the work put into a machine that is converted into useful work output; = work done / energy used [-]. = eta In machines: The work output of any machine cannot exceed the work input (<=100%); in an ideal machine, where no energy is transformed into heat: work(input) = work(output), =100%. Energy: The property of a system that enables it to do work. Conservation o. E.: Energy cannot be created or destroyed; it may be transformed from one form into another, but the total amount of energy never changes. Equilibrium: The state of an object when not acted upon by a net force or net torque; an object in equilibrium may be at rest or moving at uniform velocity - not accelerating. Mechanical E.: The state of an object or system of objects for which any impressed forces cancels to zero and no acceleration occurs. Dynamic E.: Object is moving without experiencing acceleration. Static E.: Object is at rest.F Force: The influence that can cause an object to be accelerated or retarded; is always in the direction of the net force, hence a vector quantity; the four elementary forces are: Electromagnetic F.: Is an attraction or repulsion G, gravit. const.6.672E-11[Nm2/kg2] between electric charges: d, distance [m] 2 2 2 2 F = 1/(40) (q1q2/d ) [(CC/m )(Nm /C )] = [N] m,M, mass [kg] Gravitational F.: Is a mutual attraction between all masses: q, charge [As] [C] 2 2 2 2 F = GmM/d [Nm /kg kg 1/m ] = [N] 0, dielectric constant Strong F.: (nuclear force) Acts within the nuclei of atoms: 8.854E-12 [C2/Nm2] [F/m] 2 2 2 2 2 F = 1/(40) (e /d ) [(CC/m )(Nm /C )] = [N] , 3.14 [-] Weak F.: Manifests itself in special reactions among elementary e, 1.60210 E-19 [As] [C] particles, such as the reaction that occur in radioactive decay. -
Constructing a Galactic Coordinate System Based on Near-Infrared and Radio Catalogs
A&A 536, A102 (2011) Astronomy DOI: 10.1051/0004-6361/201116947 & c ESO 2011 Astrophysics Constructing a Galactic coordinate system based on near-infrared and radio catalogs J.-C. Liu1,2,Z.Zhu1,2, and B. Hu3,4 1 Department of astronomy, Nanjing University, Nanjing 210093, PR China e-mail: [jcliu;zhuzi]@nju.edu.cn 2 key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210093, PR China 3 Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, PR China 4 Graduate School of Chinese Academy of Sciences, Beijing 100049, PR China e-mail: [email protected] Received 24 March 2011 / Accepted 13 October 2011 ABSTRACT Context. The definition of the Galactic coordinate system was announced by the IAU Sub-Commission 33b on behalf of the IAU in 1958. An unrigorous transformation was adopted by the Hipparcos group to transform the Galactic coordinate system from the FK4-based B1950.0 system to the FK5-based J2000.0 system or to the International Celestial Reference System (ICRS). For more than 50 years, the definition of the Galactic coordinate system has remained unchanged from this IAU1958 version. On the basis of deep and all-sky catalogs, the position of the Galactic plane can be revised and updated definitions of the Galactic coordinate systems can be proposed. Aims. We re-determine the position of the Galactic plane based on modern large catalogs, such as the Two-Micron All-Sky Survey (2MASS) and the SPECFIND v2.0. This paper also aims to propose a possible definition of the optimal Galactic coordinate system by adopting the ICRS position of the Sgr A* at the Galactic center. -
Constellations with Prominent Stars That Can Be Found Near the Meridian at 10 Pm on January 15
ONSTELLATIONS C Altitude Ruler The rotation of the Earth on its axis causes the stars to rise and set each evening. In addition, the orbit of the Earth around the Sun places different regions of the sky in our Horizon night-time view. The PLANISPHERE is an extremely useful tool for finding stars and 10 constellation in the sky, depicting not only what is currently in the sky but it also allows the 20 prediction of the rising and setting times of various celestial objects. 30 THE LAYOUT OF THE PLANISPHERE 40 50 The outer circumference of the dark blue circular disk (which is called the star wheel) you’ll notice that the wheel is divided into the 12 months, and that each month is divided into 60 individual dates. The star wheel rotates about the brass fastener, which represents the 70 North Celestial Pole. The frame of the planisphere has times along the outer edge. 80 Holding the planisphere on the southern corner you'll see "midnight" at the top. Moving Zenith counterclockwise, notice how the hours progress, through 1 AM, 2 AM, and so on through "noon" at the bottom. The hours then proceed through the afternoon and evening (1 PM, 2 PM, etc.) back toward midnight. Once you have the wheel set properly for the correct time and day, the displayed part represents what you see if you stand with the star and planet locator held directly over your head with the brass fastener toward the north. (Notice that the compass directions are also written on the corners of the frame.) Of course, you don't have to actually stand that way to make use of the Star and Planet Locator--this is just a description to help you understand what is displayed. -
Earth-Centred Universe
Earth-centred Universe The fixed stars appear on the celestial sphere Earth rotates in one sidereal day The solar day is longer by about 4 minutes → scattered sunlight obscures the stars by day The constellations are historical → learn to recognise: Ursa Major, Ursa Minor, Cassiopeia, Pegasus, Auriga, Gemini, Orion, Taurus Sun’s Motion in the Sky The Sun moves West to East against the background of Stars Stars Stars stars Us Us Us Sun Sun Sun z z z Start 1 sidereal day later 1 solar day later Compared to the stars, the Sun takes on average 3 min 56.5 sec extra to go round once The Sun does not travel quite at a constant speed, making the actual length of a solar day vary throughout the year Pleiades Stars near the Sun Sun Above the atmosphere: stars seen near the Sun by the SOHO probe Shield Sun in Taurus Image: Hyades http://sohowww.nascom.nasa.g ov//data/realtime/javagif/gifs/20 070525_0042_c3.gif Constellations Figures courtesy: K & K From The Beauty of the Heavens by C. F. Blunt (1842) The Celestial Sphere The celestial sphere rotates anti-clockwise looking north → Its fixed points are the north celestial pole and the south celestial pole All the stars on the celestial equator are above the Earth’s equator How high in the sky is the pole star? It is as high as your latitude on the Earth Motion of the Sky (animated ) Courtesy: K & K Pole Star above the Horizon To north celestial pole Zenith The latitude of Northern horizon Aberdeen is the angle at 57º the centre of the Earth A Earth shown in the diagram as 57° 57º Equator Centre The pole star is the same angle above the northern horizon as your latitude. -
M204; the Doppler Effect
MISN-0-204 THE DOPPLER EFFECT by Mary Lu Larsen THE DOPPLER EFFECT Towson State University 1. Introduction a. The E®ect . .1 b. Questions to be Answered . 1 2. The Doppler E®ect for Sound a. Wave Source and Receiver Both Stationary . 2 Source Ear b. Wave Source Approaching Stationary Receiver . .2 Stationary c. Receiver Approaching Stationary Source . 4 d. Source and Receiver Approaching Each Other . 5 e. Relative Linear Motion: Three Cases . 6 f. Moving Source Not Equivalent to Moving Receiver . 6 g. The Medium is the Preferred Reference Frame . 7 Moving Ear Away 3. The Doppler E®ect for Light a. Introduction . .7 b. Doppler Broadening of Spectral Lines . 7 c. Receding Galaxies Emit Doppler Shifted Light . 8 4. Limitations of the Results . 9 Moving Ear Toward Acknowledgments. .9 Glossary . 9 Project PHYSNET·Physics Bldg.·Michigan State University·East Lansing, MI 1 2 ID Sheet: MISN-0-204 THIS IS A DEVELOPMENTAL-STAGE PUBLICATION Title: The Doppler E®ect OF PROJECT PHYSNET Author: Mary Lu Larsen, Dept. of Physics, Towson State University The goal of our project is to assist a network of educators and scientists in Version: 4/17/2002 Evaluation: Stage 0 transferring physics from one person to another. We support manuscript processing and distribution, along with communication and information Length: 1 hr; 24 pages systems. We also work with employers to identify basic scienti¯c skills Input Skills: as well as physics topics that are needed in science and technology. A number of our publications are aimed at assisting users in acquiring such 1. -
And Are Lines on Sphere B That Contain Point Q
11-5 Spherical Geometry Name each of the following on sphere B. 3. a triangle SOLUTION: are examples of triangles on sphere B. 1. two lines containing point Q SOLUTION: and are lines on sphere B that contain point Q. ANSWER: 4. two segments on the same great circle SOLUTION: are segments on the same great circle. ANSWER: and 2. a segment containing point L SOLUTION: is a segment on sphere B that contains point L. ANSWER: SPORTS Determine whether figure X on each of the spheres shown is a line in spherical geometry. 5. Refer to the image on Page 829. SOLUTION: Notice that figure X does not go through the pole of ANSWER: the sphere. Therefore, figure X is not a great circle and so not a line in spherical geometry. ANSWER: no eSolutions Manual - Powered by Cognero Page 1 11-5 Spherical Geometry 6. Refer to the image on Page 829. 8. Perpendicular lines intersect at one point. SOLUTION: SOLUTION: Notice that the figure X passes through the center of Perpendicular great circles intersect at two points. the ball and is a great circle, so it is a line in spherical geometry. ANSWER: yes ANSWER: PERSEVERANC Determine whether the Perpendicular great circles intersect at two points. following postulate or property of plane Euclidean geometry has a corresponding Name two lines containing point M, a segment statement in spherical geometry. If so, write the containing point S, and a triangle in each of the corresponding statement. If not, explain your following spheres. reasoning. 7. The points on any line or line segment can be put into one-to-one correspondence with real numbers. -
The Coriolis Effect in Meteorology
THE CORIOLIS EFFECT IN METEOROLOGY On this page I discuss the rotation-of-Earth-effect that is taken into account in Meteorology, where it is referred to as 'the Coriolis effect'. (For the rotation of Earth effect that applies in ballistics, see the following two Java simulations: Great circles and Ballistics). The rotating Earth A key consequence of the Earth's rotation is the deviation from perfectly spherical form: there is an equatorial bulge. The bulge is small; on Earth pictures taken from outer space you can't see it. It may seem unimportant but it's not: what matters for meteorology is an effect that arises from the Earth's rotation and Earth's oblateness together. A model: parabolic dish Thinking about motion over the Earth's surface is rather complicated, so I turn now to a model that is simpler but still presents the feature that gives rise to the Coriolis effect. Source: PAOC, MIT Courtesy of John Marshall The dish in the picture is used by students of Geophysical Fluid Dynamics for lab exercises. This dish was manufactured as follows: a flat platform with a rim was rotating at a very constant angular velocity (10 revolutions per minute), and a synthetic resin was poured onto the platform. The resin flowed out, covering the entire area. It had enough time to reach an equilibrium state before it started to set. The surface was sanded to a very smooth finish. Also, note the construction that is hanging over the dish. The vertical rod is not attached to the table but to the dish; when the dish rotates the rod rotates with it. -
Educator's Guide: Orion
Legends of the Night Sky Orion Educator’s Guide Grades K - 8 Written By: Dr. Phil Wymer, Ph.D. & Art Klinger Legends of the Night Sky: Orion Educator’s Guide Table of Contents Introduction………………………………………………………………....3 Constellations; General Overview……………………………………..4 Orion…………………………………………………………………………..22 Scorpius……………………………………………………………………….36 Canis Major…………………………………………………………………..45 Canis Minor…………………………………………………………………..52 Lesson Plans………………………………………………………………….56 Coloring Book…………………………………………………………………….….57 Hand Angles……………………………………………………………………….…64 Constellation Research..…………………………………………………….……71 When and Where to View Orion…………………………………….……..…77 Angles For Locating Orion..…………………………………………...……….78 Overhead Projector Punch Out of Orion……………………………………82 Where on Earth is: Thrace, Lemnos, and Crete?.............................83 Appendix………………………………………………………………………86 Copyright©2003, Audio Visual Imagineering, Inc. 2 Legends of the Night Sky: Orion Educator’s Guide Introduction It is our belief that “Legends of the Night sky: Orion” is the best multi-grade (K – 8), multi-disciplinary education package on the market today. It consists of a humorous 24-minute show and educator’s package. The Orion Educator’s Guide is designed for Planetarians, Teachers, and parents. The information is researched, organized, and laid out so that the educator need not spend hours coming up with lesson plans or labs. This has already been accomplished by certified educators. The guide is written to alleviate the fear of space and the night sky (that many elementary and middle school teachers have) when it comes to that section of the science lesson plan. It is an excellent tool that allows the parents to be a part of the learning experience. The guide is devised in such a way that there are plenty of visuals to assist the educator and student in finding the Winter constellations. -
The Sundial Cities
The Sundial Cities Joel Van Cranenbroeck, Belgium Keywords: Engineering survey;Implementation of plans;Positioning;Spatial planning;Urban renewal; SUMMARY When observing in our modern cities the sun shade gliding along the large surfaces of buildings and towers, an observer can notice that after all the local time could be deduced from the position of the sun. The highest building in the world - the Burj Dubai - is de facto the largest sundial ever designed. The principles of sundials can be understood most easily from an ancient model of the Sun's motion. Science has established that the Earth rotates on its axis, and revolves in an elliptic orbit about the Sun; however, meticulous astronomical observations and physics experiments were required to establish this. For navigational and sundial purposes, it is an excellent approximation to assume that the Sun revolves around a stationary Earth on the celestial sphere, which rotates every 23 hours and 56 minutes about its celestial axis, the line connecting the celestial poles. Since the celestial axis is aligned with the axis about which the Earth rotates, its angle with the local horizontal equals the local geographical latitude. Unlike the fixed stars, the Sun changes its position on the celestial sphere, being at positive declination in summer, at negative declination in winter, and having exactly zero declination (i.e., being on the celestial equator) at the equinoxes. The path of the Sun on the celestial sphere is known as the ecliptic, which passes through the twelve constellations of the zodiac in the course of a year. This model of the Sun's motion helps to understand the principles of sundials. -
Determining the Motion of Galaxies Using Doppler Redshift
Determining the Motion of Galaxies Using Doppler Redshift Caitlin M. Matyas The Arts Academy at Benjamin Rush Overview Rationale Objective Strategies Classroom Activities Annotated Bibliography / Resources Standards Appendices Overview The Doppler effect of sound is a method used to determine the relative speeds of an object emitting a sound and an observer. Depending on whether the source and/or observer are moving towards or away from each other, the frequency of the wave will change. This in turn creates a change in pitch perceived by the observer. The relative speeds can easily be calculated using the following formula: � ± �′ = �( ), � ± where f’ represents the shifted frequency, f represents the frequency of the source, v is the speed of sound, vo is the speed of the observer, and vs is the speed of the source. Vo is added if moving towards and subtracted if moving away from the source. vs is added if moving away and subtracted if moving towards the observer. The figures below help to demonstrate the perceived change in frequency. The source is located at the center of the smallest circle. The picture shows waves expanding as they move outwards away from the source, so the earliest emitted waves create the biggest circles. If both the source and observer were stationary, the waves appear to pass at equal periods of time, as seen in figure IA. However, if the source is moving, the frequency appears to change. Figure IB shows what would happen if the source moves towards the right. Although the waves are emitted at a constant frequency, they seem closer together on the right side and farther spaced on the left. -
2. Descriptive Astronomy (“Astronomy Without a Telescope”)
2. Descriptive Astronomy (“Astronomy Without a Telescope”) http://apod.nasa.gov/apod/astropix.html • How do we locate stars in the heavens? • What stars are visible from a given location? • Where is the sun in the sky at any given time? • Where are you on the Earth? An “asterism” is two stars that appear To be close in the sky but actually aren’t In 1930 the International Astronomical Union (IAU) ruled the heavens off into 88 legal, precise constellations. (52 N, 36 S) Every star, galaxy, etc., is a member of one of these constellations. Many stars are named according to their constellation and relative brightness (Bayer 1603). Sirius α − Centauri, α-Canis declination less http://calgary.rasc.ca/constellation.htm - list than -53o not Majoris, α-Orionis visible from SC http://www.google.com/sky/ Betelgeuse https://en.wikipedia.org/wiki/List_of_Messier_objects (1758 – 1782) Biggest constellation – Hydra – the female water snake 1303 square degrees, but Ursa Major and Virgo almost as big. Hydrus – the male water snake is much smaller – 2243 square degrees Smallest is Crux – the Southern Cross – 68 square degrees Brief History Some of the current constellations can be traced back to the inhabitants of the Euphrates valley, from whom they were handed down through the Greeks and Arabs. Few pictorial records of the ancient constellation figures have survived, but in the Almagest AD 150, Ptolemy catalogued the positions of 1,022 of the brightest stars both in terms of celestial latitude and longitude, and of their places in 48 constellations. The Ptolemaic constellations left a blank area centered not on the present south pole but on a point which, because of precession, would have been the south pole c. -
Glossary | Speed Measuring Device Resources 191.94 KB
GLOSSARY Absorption - The transmitted R.A.D.A.R. beam will, unless otherwise acted upon (absorbed, reflected, or refracted), travel infinitely far. Under practical circumstances, the beam may be partially absorbed by natural and man-made substances. Vegetation such as trees, grass, and bushes will absorb R.A.D.A.R. energy. Freshly turned earth, such as that in a freshly plowed field, will also absorb R.A.D.A.R. Plastics of certain types and foam products will absorb R.A.D.A.R., as makers of "stealth" automotive accessories have discovered. Absorption of R.A.D.A.R. will not result in any inaccuracies in the R.A.D.A.R. readings. It will reduce the strength of the returned signal, and the operational range of the device depending upon the circumstances. Absolute speed limits - Holds that a given speed limit is in force, regardless of environment conditions, i.e., 35 mph or 50 mph. Accuracy - When used in conjunction with R.A.D.A.R. devices means the degree to which the R.A.D.A.R. device measures and displays the correct speed of a target vehicle that it is tracking. Ambient interference - The conducted and/or radiated electromagnetic interference and/or mechanical motion interference at a specific location and at a time which would be detrimental to proper R.A.D.A.R. performance. Antenna horn - The antenna horn is that portion of the R.A.D.A.R. device that shapes and directs the microwave energy (beam). The antenna horn also "catches" the returning microwave energy and directs it to the R.A.D.A.R.