The Universe Adventure - Standard Candles. Standard Candles It is easy to measure the intensity (observed brightness) of an object from Earth, but how do we know the luminosity (intrinsic brightness) of the object? There are certain objects whose luminosity is always the same no matter where they appear in the universe, and we can use that fact to determine their distance from Earth. These types of objects are called "standard candles". To measure distances across the universe, we need objects that are incredibly bright (so we can see them). For this reason astrophysicists use a particular type of supernova that always has the same peak luminosity.
Finding out the relationship between these two is a lot like finding the difference between absolute and apparent magnitudes. Solution You may notice that the units of luminosity (Watts) are very close to the units of intensity (Watts/m2). Giving us a nice result for the distance, r. Plugging in our numbers: and we see that r=1.1×1017 m, or 11.6 light years. Proton-Proton Animation. Shows an animated diagram of the proton-proton chain reaction, which is the dominant fusion reaction in the sun's core.
Running this animation on your computer... right-click to download fusion01.swf and fusion01.html to the same directory open the html file in a browser to run the animation Linking to this animation... copy and paste the code below into your webpage or blog: Putting this animation on your website... upload fusion01.swf to the same directory as your webpage copy and paste the following code into your webpage: 15 Min Objective Test series for Mechanics for IITJEE,AIEEE,PMT – Learn physics through notes and study material. Multiple choice question with one or more answer 1. Which of these is true of a conservative force?
A. Workdone between two points is independent of the pathb. Workdone in a closed loop is zeroc. if the workdone by the conservative is positive,its potential energy increasesd. None of the these 2.A particle is acted upon by a force of costant magnitude which is always perpendicular to the velocity of the particle.The motion of the particle takes place in a plane.it follows thata. velocity is constantb. accelerattion is constantc. 3. 4.A small mass m is suspended from one end of a vertical string. and then whirled in a horizontal circle at a constant speed v.Which of the followings is truea.The strings stays verticalb.The string becomes inclined to the vertical.c.There is no force on mass m except its weightd.The angle of inclination of the string does not depend on the ve.The centripetal force on m is mg 9. 10.
Solutions1.a,b2.c,d3.a,b4. b5. a,b,c,d6. c,d7. c8 a9 a10 b,d. Pioneer anomaly. The Pioneer anomaly or Pioneer effect is the observed deviation from predicted accelerations of the Pioneer 10 and Pioneer 11 spacecraft after they passed about 20 astronomical units (3×109 km; 2×109 mi) on their trajectories out of the Solar System. The apparent anomaly was a matter of tremendous interest for many years.
Both Pioneer spacecraft are escaping the Solar System, but are slowing under the influence of the Sun's gravity. Upon very close examination of navigational data, the spacecraft were found to be slowing slightly more than expected. The effect is an extremely small acceleration towards the Sun, of (8.74±1.33)×10−10 m/s2, which is equivalent to slowly accelerating to a velocity of one kilometer per hour (0.6 mph) over a period of ten years. Various explanations, both of spacecraft behavior and of gravitation itself, were proposed to explain the anomaly.
Description[edit] Pioneer 10 and 11 were sent on missions to Jupiter and Jupiter/Saturn respectively. Gravity[edit] Transformers Part 1 - Beginners' Guide to Electronics. Transformers - The Basics (Section 1)Copyright © 2001 - Rod Elliott (ESP) Page Published & Updated 24 Mar 2001 Articles Index Main Index Contents - Section 1 Preface One thing that obviously confuses many people is the idea of flux density within the transformer core. For any power transformer, the maximum flux density is obtained when the transformer is idle. The idea is counter-intuitive, it even verges on not making sense. It is not important that you understand the reasons for this right from the beginning, but it is important that you remember that for any power transformer, the maximum flux density is obtained when the transformer is idle. Introduction As you look through this article, you may be excused for exclaiming "This is for beginners? There are parts of this article you may want to skip over, but I suggest that you do read all of it if you can.
For those who wish to delve deeper, Section 2 does just that. Power transformers are rated in Volt-Amps (VA). Split Bobbin E-I Plug-Pack. Kessler syndrome. Space debris populations seen from outside geosynchronous orbit (GEO). There are two primary debris fields, the ring of objects in GEO, and the cloud of objects in low earth orbit (LEO). The Kessler syndrome (also called the Kessler effect,[1][2] collisional cascading or ablation cascade), proposed by the NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) is high enough that collisions between objects could cause a cascade—each collision generating space debris which increases the likelihood of further collisions.[3] One implication is that the distribution of debris in orbit could render space exploration, and even the use of satellites, unfeasible for many generations.[3] Debris generation and destruction[edit] Every satellite, space probe, and manned mission has the potential to create space debris.
Implications[edit] Image made from models used to track debris in Earth orbit. Avoidance and reduction[edit] See also[edit] Physical Review X. Science Questions with Surprising Answers. Low Earth Orbit. Want to stay on top of all the space news? Follow @universetoday on Twitter Estimated number of objects in low Earth orbit. Credit: NASA Low Earth Orbit is an orbit that extends from the Earth’s surface at sea level to an altitude of 2,000 km.
What is interesting about the majority of Low Earth Orbit is that most of it lies within the Earth’s atmosphere. Low Earth Orbit is a region that includes Earth at Sea Level and up to 2000 kilometers above sea level. Low Earth Orbit has been used for both military and aeronautical purposes. Other than lunar flights Low Earth Orbit defines the boundary of all human space exploration. We have written many articles about low Earth orbit for Universe Today. If you’d like more info on low Earth orbit, check out the types of orbit from the European Space Agency website. We’ve also recorded an entire episode of Astronomy Cast all about Getting Around the Solar System. Tagged as: low earth orbit, low orbit, spaceflight.
The Habitable Exoplanets Catalog. The figure above shows all planets near the habitable zone (darker green shade is the conservative habitable zone and the lighter green shade is the optimistic habitable zone). Only those planets less than 10 Earth masses or 2.5 Earth radii are labeled. The different limits of the habitable zone are described in Kopparapu et al. (2014). Size of the circles corresponds to the radius of the planets (estimated from a mass-radius relationship when not available). Larger version here. Credit: PHL @ UPR Arecibo. Location in the night sky of all the known stellar systems with potentially habitable worlds (some systems have more than one planet). The Periodic Table of Exoplanets shows all known exoplanets, including a few still unconfirmed, classified into eighteen thermal-mass categories. Chart of the Nuclides 2010. WWW Chart of the Nuclides here is based on the compilation of experimental data until 2008 by H. Koura (JAEA), T. Tachibana (Waseda University), and J.
Katakura (JAEA), beta-decay half-lives estimated, by T. Tachibana, with the Gross Theory [T. Tachibana, M. Yamada, Proc. A printed version of Chart of the Nuclides 2010, compiled by T. In this WWW Chart of the Nuclides, a decay mode of ground state is indicated with decay mode pattern. By clicking a box of each nuclide, information on the nuclide is shown, which contains spin and half-life, mass, strong gamma-rays from nuclear decay, decay data, and links to figures and tables of cross-section data stored in Japanese evaluated nuclear data library JENDL-4.0.
When a box of atomic numbers located at the left side is clicked, an isotope list of corresponding element is displayed. WWW Chart of the Nuclides 2010 was created by using gd2.0.35 which was originally developed by Thomas Boutell and is now maintained by Pierre-A. Nuclear Physics: The Core of Matter, The Fuel of Stars. Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages. Do not use for reproduction, copying, pasting, or reading; exclusively for search engines. OCR for page 19 --> 2 The Structure of the Nuclear Building Blocks Introduction It is a remarkable fact of nature that the average distance between protons and neutrons inside an atomic nucleus is only half again as large as the individual protons and neutrons themselves.
OCR for page 19 --> within neutrons, protons, or other strongly interacting particles built from quarks and gluons. Jamie's Joke of the Week #2. Trimix (breathing gas) Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used in deep commercial diving and during the deep phase of dives carried out using technical diving techniques.[1][2] With a mixture of three gases it is possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas. The mixture of helium and oxygen with a 0% nitrogen content is generally known as Heliox. This is frequently used as a breathing gas in deep commercial diving operations, where it is often recycled to save the expensive helium component. Analysis of two-component gases is much simpler than three component gases. The main reason for adding helium to the breathing mix is to reduce the proportions of nitrogen and oxygen below those of air, to allow the gas mix to be breathed safely on deep dives.[1] A lower proportion of nitrogen is required to reduce nitrogen narcosis and other physiological effects of the gas at depth.
Joint Entrance Examination (Advanced) - 2013 (JEE (Advanced) - 2013) Physics. Energy and Momentum in Nuclear Reactors Topics| Particles Faysal Riaz, Jan 1999 Here is my attempt at most of the problems in ' Energy and Momentum in Nuclear Reactors' Question 1 - Explain why gamma rays would be emitted during an inelastic collision between a neutron and a target atomic nucleus. During the inelastic collision the target nucleus emits alpha and beta particles and so becomes more energetic. Question 2 - Determine the speed of a 1 MeV neutron using a non-relativistic formula for kinetic energy and hence determine whether relativistic mechanics are to be used in any further working. 1 MeV = 1 ´ 106 eV m = 1.674 ´ 10-27 kg \ KMAX = 1/2 mv2 1.6 ´ 10-13 = 1/2 ´ 1.674 ´ 10-27 ´ v2 \ v = Ö (1.6 ´ 10-13) ¸Ö (1/2 ´ 1.674 ´ 10-27) = 1.4 ´ 107 ms-1 This speed is five hundredths of the speed of light, so I do not have to use relativistic mechanics in any further working, I will use Newtonian mechanics.
(a) m1 (u1 - v1) = m2v2 m1u1 + m2u2 = m1v1 + m2v2 u2 = 0 m1u1 - m1v1 = m2v2 m1u12 - m1v12 = m2v22. Atomic Collision definition of Atomic Collision in the Free Online Encyclopedia. Warning! The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased. an elementary collision event between two atomic particles, which may be atoms, molecules, electrons, or ions. Such a collision is either elastic or inelastic. Elastic collisions account for transport phenomena in gases or weakly ionized plasmas. In the case where atoms or molecules with thermal energies are scattered at large angles, the elastic cross section is known as the gas-kinetic cross section.
Elastic scattering at small angles may affect the nature of the transfer of electromagnetic radiation in a gas. Phase or frequency. Many different inelastic collision processes have been observed. McDaniel, E. Periodic Table | Minute Physics. Thermal lance. Thermal lance cutting a railroad bridge to prepare for replacement. A thermal lance, thermic lance, oxygen lance, or burning bar is a tool that heats and melts iron in the presence of pressurized oxygen to create the very high temperatures required for cutting. It consists of a long iron tube packed with iron rods, sometimes mixed with aluminium or magnesium rods to increase the heat output. One end of the tube is placed in a holder and oxygen is fed through the tube. The far end of the tube is pre-heated and lit by an oxyacetylene torch. An intense stream of burning iron is produced at the workpiece end and can be used to cut rapidly through thick materials including steel and concrete.
The tube is consumed, so every few minutes the operator shuts off the oxygen, discards the remaining stub of a lance tube and starts using a new one. Popular misconceptions[edit] In popular culture[edit] See also[edit] Thermite References[edit] External links[edit] U.S. College Intro Chem Lab Manual: Summary of Sig Figs and Uncertainty. Kendama. A traditional Kendama A kendama (けん玉 ? , also written as 剣玉 and 拳玉) is a traditional Japanese toy which consists of three wooden cups of different sizes placed on the center of a wooden spike, with a smaller cup at the spike's base and a ball connected by a string to the center piece.
In English, kendama may be referred to as ring and pin and bears similarities to the classic cup-and-ball game, similar to the Hispanic world toy known as boliche or balero. The principle of these toys are the same: catching one object with another, where both are joined by a string. Structure and terminology[edit] Red Ozora kendama made in Japan, with emblem indicating approval by the Japanese Kendama Association for competition use The main body of the kendama is called the ken (剣?). Origins and precursors[edit] A French bilboquet, a forerunner of the kendama The origins of the game are obscure. It is known in places as diverse as the Arctic, France, and Peru. Japanese history[edit] Usage[edit] References[edit] Pogo stick. Derek Leinweber. Amazing Science-X Challenge. Www.phys.uwosh.edu/rioux/genphysii/pdf/rainbows.pdf. Amazing Science Tricks. Your Northern Home: Stack effect. C.ymcdn.com/sites/www.eps.org/resource/collection/016775D4-8888-474D-887F-3E33AEA5E6D0/EPSPED_MUSE_bot_holes.pdf.
FREE 21st Century Lesson Plans & Teaching Tools. Www.phy.duke.edu/~rgb/Class/intro_physics_1/intro_physics_1.pdf. Lektronika : books : Understanding electronic components. Hong Kong Physics Olympiad. Super-Kamiokande Official Homepage.