DOCSLIB.ORG

Apparent Weightlessness and Artificial Gravity

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Apparent Weightlessness and Artificial Gravity Apparent Weightlessness and Artificial Gravity • In order to simulate weightlessness it is necessary to eliminate the effect of air resistance. • To accomplish this a plane it used to fly passengers first upwards at a high acceleration. When the plane begins to maintain a steady arc at the top, the normal force becomes zero giving the impression of weightlessness. • NASA Low g plane Lecture 13 Neat Videos • Drinking coffee in Low g • Drinking water • Water Balloons in Low g Apparent Weightlessness and Artificial Gravity • In space far from the earth astronauts are in a perpetual state of weightlessness. • In order to make space-goers more comfortable it is possible to use the effects of uniform circular motion to simulate the effects of gravity. • By constructing a space station is the form of the cylinder the floor would provide the necessary centripetal force necessary to get objects going around in a circle. Lecture 13 4.7 The Gravitational Force Newton’s Law of Universal Gravitation Every particle in the universe exerts an attractive force on every other particle. A particle is a piece of matter, small enough in size to be regarded as a mathematical point. The force that each exerts on the other is directed along the line joining the particles. 4.7 The Gravitational Force For two particles that have masses m1 and m2 and are separated by a distance r, the force has a magnitude given by m m F G 1 2 r 2 G 6.673 10 11 N m2 kg 2 Three interesting examples: a. Calculate the gravitational force between the earth and a 60 kg person b. Calculate the gravitational force between two 60 kg people one meter apart c. Calculate the gravitational force between the earth and moon THESE NUMERICAL EXAMPLES ARE ONLY PRESENTED TO SHOW THE SIZE OF THE GRAITATINAL FORCE.YOU DON’T NEED TO BE ABLE TO DO THEM! Example a: 11 24 GM pM E 6.67x10 * 60 * 6x10 Fg = = N = 588N r2 (6.38x10 6 )2 2 and W = mg = 60kg * 9.8m/s = 588N (same answer!) Formula for weight and universal law of gravity give the same answer. GM This is because in formula W=mg g = E 2 r Example B: FORCE BETWEEN TWO 60 KG PEOPLE 11 GM pM E 6.67x10 * 60 * 60 Fg = = N = .00000024N r2 (1)2 THE FORCE IS VERY SMALL!! Example C: FORCE BETWEEN EARTH AND MOON 11 24 22 GM pM E 6.67x10 * 6x10 * 7.35x10 20 Fg = = N = 1.98X10 N 2 8 2 r (3.85x10 ) THIS FORCE IS VERY LARGE! GRAVITY IS THE WEAKEST OF THE FOUR FUNDAMENTAL FORCES BUT CAN BE LARGE WHEN THE MASSES INVOLVED ARE LARGE. Satellite Motion A projectile launched from the center of the earth will fall back to earth until... The speed of a satellite at a distance r from the earth’s center is: GM V = Earth S r Note that the mass of the satellite does not appear in the equation. This means that the speed of a satellite in orbit DOES NOT depend on the satellite mass so all objects in this orbit will move at the same speed irregardless of size. How fast is this speed? Example: International Space Station r=6380km+340 km=6780km 24 MEarth=6x10 kg 11 24 GM 6.67x10 6x10 VS = = r Earth 6780x103 = 7683m/s = 27,658 km/h!! The ISS which is only 340km above the earth must travel at 27,658 km/h in order to stay in that orbit. THIS IS VERY FAST!! Some Interesting stuff... GLOBAL POSITIONING SYSTEM(GPS) • The first GPS satellite was launched in 1978. • A full constellation of 24 satellites was achieved in 1994. • Each satellite is built to last about 10 years. Replacements are constantly being built and launched into orbit. • A GPS satellite weighs approximately 2,000 pounds and is about 17 feet across with the solar panels extended. • Transmitter power is only 50 watts or less. Global Positioning System Global Positioning System • The GPS system works by having the satellite send radio waves which carry precise time measurements. • When receivers on the earth detect the waves they can calculate the radial distance they are from the satellite. Global Positioning System • Therefore the signal from one satellite allows people to determine where they are located within a circle. • When two other satellites are used, the receiver can determine a more precise location..
Load more

Recommended publications
  • 5-8 Satellites and “Weightlessness” Objects in Orbit Are Said to Experience Weightlessness
    5-8 Satellites and “Weightlessness” Objects in orbit are said to experience weightlessness. They do have a gravitational force acting on them, though! The satellite and all its contents are in free fall, so there is no normal force. This is what leads to the experience of weightlessness. 5-8 Satellites and “Weightlessness” More properly, this effect is called apparent weightlessness, because the gravitational force still exists. It can be experienced on Earth as well, but only briefly: Calculating the Local Force of Gravity So the local gravitational acceleration depends upon your distance from the center of mass. Usually this is your distance from the center of the Earth ConcepTest 5.9 Fly Me Away You weigh yourself on a scale inside an airplane that is flying with constant 1) greater than speed at an altitude of 20,000 feet. 2) less than How does your measured weight in the 3) same airplane compare with your weight as measured on the surface of the Earth? ConcepTest 5.9 Fly Me Away You weigh yourself on a scale inside an airplane that is flying with constant 1) greater than speed at an altitude of 20,000 feet. 2) less than How does your measured weight in the 3) same airplane compare with your weight as measured on the surface of the Earth? At a high altitude, you are farther away from the center of Earth. Therefore, the gravitational force in the airplane will be less than the force that you would experience on the surface of the Earth. ConcepTest 5.10 Two Satellites Two satellites A and B of the same mass 1) 1/8 are going around Earth in concentric 2) 1/4 orbits.
    [Show full text]
  • PHYSICS of ARTIFICIAL GRAVITY Angie Bukley1, William Paloski,2 and Gilles Clément1,3
    Chapter 2 PHYSICS OF ARTIFICIAL GRAVITY Angie Bukley1, William Paloski,2 and Gilles Clément1,3 1 Ohio University, Athens, Ohio, USA 2 NASA Johnson Space Center, Houston, Texas, USA 3 Centre National de la Recherche Scientifique, Toulouse, France This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented. Figure 2-01. Artist's concept of one of NASA early (1962) concepts for a manned space station with artificial gravity: a self- inflating 22-m-diameter rotating hexagon. Photo courtesy of NASA. 1 ARTIFICIAL GRAVITY: WHAT IS IT? 1.1 Definition Artificial gravity is defined in this book as the simulation of gravitational forces aboard a space vehicle in free fall (in orbit) or in transit to another planet. Throughout this book, the term artificial gravity is reserved for a spinning spacecraft or a centrifuge within the spacecraft such that a gravity-like force results. One should understand that artificial gravity is not gravity at all. Rather, it is an inertial force that is indistinguishable from normal gravity experience on Earth in terms of its action on any mass. A centrifugal force proportional to the mass that is being accelerated centripetally in a rotating device is experienced rather than a gravitational pull.
    [Show full text]
  • Various Study Papers Download
    33 rd Canadian Medical and Biological Engineering Society Conference œ Vancouver œ June 15-18 2010 Topic Area - Physiological systems and models. Plantar Biophotonic Stimulation improves Ocular-motor and Postural Control in Motor Vehicle Accident Patients. Amanmeet Garg a, Michelle Bruner a, Philippe A. Souvestre b, Andrew P. Blaber a a) Department of Biomedical Physiology and Kinesiology, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada. b) NeuroKinetics Health Services B.C. Inc., Suite 60 Hycroft Centre, 3195 Granville Street, Vancouver, BC, Canada. Introduction: Worldwide road accident related statistics reflect a consistent increase of motor vehicle accidents (MVA). Survivors of motor vehicle accidents experience a range of head injuries from whiplash, concussion, and mild to severe traumatic brain injuries, of which the most severe may result in incapacitation or death. Central sensory-motor controls (SMC), including ocular-visual, ocular-motor, vestibular, and cerebellar systems are primarily affected. Methods: Visual-ocular convergence (VOC) and postural balance (PB) tests are used among others to measure the degree of central sensory-motor controls dysfunction. This retrospective study (n=19) investigates the effect of passive biophotonic stimulation applied to plantar postural sensory afferents on VOC and PB tests conducted during a neurophysiological evaluation. Stabilogram diffusion analysis (SDA) of the centre of pressure trajectory from the PB test was used to determine the amount of stochastic activity and dynamic behavior of postural control (Collins and De Luca, Exp Brain Res 95:308-318, 1993). Results: Visual-ocular convergence was significantly closer (p<0.001) with stimulation (5.3±1.0 cm) than without (11±1.0 cm).
    [Show full text]
  • Thought Experiments in Teaching Free-Fall Weightlessness: a Critical Review and an Exploration of Mercury’S Behavior in “Falling Elevator”
    OPEN ACCESS EURASIA Journal of Mathematics Science and Technology Education ISSN: 1305-8223 (online) 1305-8215 (print) 2017 13(5):1283-1311 DOI 10.12973/eurasia.2017.00671a Thought Experiments in Teaching Free-Fall Weightlessness: A Critical Review and an Exploration of Mercury’s Behavior in “Falling Elevator” Jasmina Balukovic Druga Gimnazija, Sarajevo, BOSNIA and HERZEGOVINA Josip Slisko Benemérita Universidad Autónoma de Puebla, MEXICO Adrián Corona Cruz Benemérita Universidad Autónoma de Puebla, MEXICO Received 9 May2016 ▪ Revised 7 June 2016 ▪ Accepted 7 June 2016 ABSTRACT Different “thought experiments” dominate teaching approaches to weightlessness, reducing students’ opportunities for active physics learning, which should include observations, descriptions, explanations and predictions of real phenomena. Besides the controversy related to conceptual definitions of weight and weightlessness, we report another controversy regarding the position of the person that weighs herself or himself in a freely-falling elevator, a “thought experiment” commonly used for introducing the concept of weightlessness. Two XIX-century “thought experiments”, one from America and one from Russia, show that they have a long tradition in physics teaching. We explored experimentally a “thought experiment” that deals with the behavior of a mercury drop in a freely-falling elevator. Our experimental results show that the mercury drop neither took the expected spherical shape nor performed oscillatory motions predicted by theory. Teachers should encourage
    [Show full text]
  • Human Adaptation and Safety in Space
    SICSA SPACE ARCHITECTURE SEMINAR LECTURE SERIES PART II : HUMAN ADAPTATION AND SAFETY IN SPACE www.sicsa.uh.edu LARRY BELL, SASAKAWA INTERNATIONAL CENTER FOR SPACE ARCHITECTURE (SICSA) GERALD D.HINES COLLEGE OF ARCHITECTURE, UNIVERSITY OF HOUSTON, HOUSTON, TX The Sasakawa International Center for SICSA routinely presents its publications, Space Architecture (SICSA), an research and design results and other organization attached to the University of information materials on its website Houston’s Gerald D. Hines College of (www.sicsa.uh.edu). This is done as a free Architecture, offers advanced courses service to other interested institutions and that address a broad range of space individuals throughout the world who share our systems research and design topics. In interests. 2003 SICSA and the college initiated Earth’s first MS-Space Architecture This report is offered in a PowerPoint format with degree program, an interdisciplinary 30 the dedicated intent to be useful for academic, credit hour curriculum that is open to corporate and professional organizations who participants from many fields. Some wish to present it in group forums. The document students attend part-time while holding is the second in a series of seminar lectures that professional employment positions at SICSA has prepared as information material for NASA, affiliated aerospace corporations its own academic applications. We hope that and other companies, while others these materials will also be valuable for others complete their coursework more rapidly who share our
    [Show full text]
  • Human Adaptation to Space
    Human Adaptation to Space From Wikipedia, the free encyclopedia Human physiological adaptation to the conditions of space is a challenge faced in the development of human spaceflight. The fundamental engineering problems of escaping Earth's gravity well and developing systems for in space propulsion have been examined for well over a century, and millions of man-hours of research have been spent on them. In recent years there has been an increase in research into the issue of how humans can actually stay in space and will actually survive and work in space for long periods of time. This question requires input from the whole gamut of physical and biological sciences and has now become the greatest challenge, other than funding, to human space exploration. A fundamental step in overcoming this challenge is trying to understand the effects and the impact long space travel has on the human body. Contents [hide] 1 Importance 2 Public perception 3 Effects on humans o 3.1 Unprotected effects 4 Protected effects o 4.1 Gravity receptors o 4.2 Fluids o 4.3 Weight bearing structures o 4.4 Effects of radiation o 4.5 Sense of taste o 4.6 Other physical effects 5 Psychological effects 6 Future prospects 7 See also 8 References 9 Sources Importance Space colonization efforts must take into account the effects of space on the body The sum of mankind's experience has resulted in the accumulation of 58 solar years in space and a much better understanding of how the human body adapts. However, in the future, industrialization of space and exploration of inner and outer planets will require humans to endure longer and longer periods in space.
    [Show full text]
  • Spaceflight Induced Changes in the Central Nervous System
    DOI: 10.5772/intechopen.74232 ProvisionalChapter chapter 5 Spaceflight InducedInduced ChangesChanges inin thethe CentralCentral NervousNervous System Alex P. Michael Additional information isis available atat thethe endend ofof thethe chapterchapter http://dx.doi.org/10.5772/intechopen.74232 Abstract Although once a widely speculated about and largely theoretical topic, spaceflightinduced intracranial hypertension is more accepted as a distinct clinical phenomenon; yet, the under- lying physiological mechanisms are still poorly understood. In the past, many terms were used to describe the symptoms of malaise, nausea, vomiting, and vertigo though longer duration spaceflights have increased the prevalence of overlapping symptoms of headache and visual disturbance. Spaceflight-induced visual pathology is thought to be a manifesta- tion of increased intracranial pressure (ICP) because of its similar presentation to cases of known intracranial hypertension on Earth as well as the documentation of increased ICP by lumbar puncture in symptomatic astronauts upon return to gravity. The most likely mecha- nisms of spaceflight-induced increased ICP include a cephalad shift of body fluids, venous outflow obstruction, blood-brain barrier breakdown, and disruption to CSF flow. The rela- tive contribution of increased ICP to the symptoms experienced during spaceflight is cur- rently unknown though as other factors recently posited to contribute include local effects on ocular structures, individual differences in metabolism, and the vasodilator effects of carbon dioxide. Spaceflight-induced intracranial hypertension must be distinguished from other pathologies with similar symptomatology. The following chapter discusses the pro- posed physiologic causes and the pathological manifestations of increased ICP in the space- flight environment and provides considerations for future long-term space travel.
    [Show full text]
  • Exploring Artificial Gravity 59
    Exploring Artificial gravity 59 Most science fiction stories require some form of artificial gravity to keep spaceship passengers operating in a normal earth-like environment. As it turns out, weightlessness is a very bad condition for astronauts to work in on long-term flights. It causes bones to lose about 1% of their mass every month. A 30 year old traveler to Mars will come back with the bones of a 60 year old! The only known way to create artificial gravity it to supply a force on an astronaut that produces the same acceleration as on the surface of earth: 9.8 meters/sec2 or 32 feet/sec2. This can be done with bungee chords, body restraints or by spinning the spacecraft fast enough to create enough centrifugal acceleration. Centrifugal acceleration is what you feel when your car ‘takes a curve’ and you are shoved sideways into the car door, or what you feel on a roller coaster as it travels a sharp curve in the tracks. Mathematically we can calculate centrifugal acceleration using the formula: V2 A = ------- R Gravitron ride at an amusement park where V is in meters/sec, R is the radius of the turn in meters, and A is the acceleration in meters/sec2. Let’s see how this works for some common situations! Problem 1 - The Gravitron is a popular amusement park ride. The radius of the wall from the center is 7 meters, and at its maximum speed, it rotates at 24 rotations per minute. What is the speed of rotation in meters/sec, and what is the acceleration that you feel? Problem 2 - On a journey to Mars, one design is to have a section of the spacecraft rotate to simulate gravity.
    [Show full text]
  • NEAR of the 21 Lunar Landings, 19—All of the U.S
    Copyrights Prof Marko Popovic 2021 NEAR Of the 21 lunar landings, 19—all of the U.S. and Russian landings—occurred between 1966 and 1976. Then humanity took a 37-year break from landing on the moon before China achieved its first lunar touchdown in 2013. Take a look at the first 21 successful lunar landings on this interactive map https://www.smithsonianmag.com/science-nature/interactive-map-shows-all-21-successful-moon-landings-180972687/ Moon 1 The near side of the Moon with the major maria (singular mare, vocalized mar-ray) and lunar craters identified. Maria means "seas" in Latin. The maria are basaltic lava plains: i.e., the frozen seas of lava from lava flows. The maria cover ∼ 16% (30%) of the lunar surface (near side). Light areas are Lunar Highlands exhibiting more impact craters than Maria. The far side is pocked by ancient craters, mountains and rugged terrain, largely devoid of the smooth maria we see on the near side. The Lunar Reconnaissance Orbiter Moon 2 is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit. LRO data is essential for planning NASA's future human and robotic missions to the Moon. Launch date: June 18, 2009 Orbital period: 2 hours Orbit height: 31 mi Speed on orbit: 0.9942 miles/s Cost: 504 million USD (2009) The Moon is covered with a gently rolling layer of powdery soil with scattered rocks called the regolith; it is made from debris blasted out of the Lunar craters by the meteor impacts that created them.
    [Show full text]
  • Weightlessness and Rocket Propulsion
    Weightlessness and Rocket Propulsion 1 Risks of Long Term Space Flight and How to Mi?gate Them 2 How do we measure radiaon? In SI units, the amount of radiaon absorbed is measured in Grays (Gy): 1 Gy = 1 joule of energy absorbed per kilogram of material (Another unit you see is “rad”, where 1 rad = 0.01 Gy) For human dosage, we typically talk about mGy. Radiaon deposits energy in uniQue ways into biological systems. milliSieverts (mSv) describes the biological eQuivalent radiaon dosage. (an older unit called the “rem”) This number has the same units as Grays, but it does not measure the same thing. Sieverts take into account the type of radiaon and the biological damage it can cause. 3 How do we measure radiaon? Let’s look at some typical numbers: An average six month stay aboard the ISS: Dose will be higher for astronauts • 80 mSv (solar max) par?cipang in space walks. (Note: • 160 mSv (solar min) NASA avoids spacewalks during • 1 mSv is approximately eQuivalent to 3 high risk periods) chest X-rays (Note: the radiaon is different) • NASA limits exposure to 200 mSv/yr • NCRP limits flight crews to 500 mSv/yr Typical radiaon dose on Earth is 2 mSv/yr due to background radiaon. hap://www.epa.gov/rpdweb00/understand/calculate.html This will vary with al?tude, proximity to nuclear power, local geology, and other 4 factors. What is NASA doing to protect astronauts? NASA follows the protec?on prac?ces that are recommended by the US Naonal Academy of Space Science Board and the US Council on Radiaon Protec?on and Measurement.
    [Show full text]
  • ARTIFICIAL GRAVITY RESEARCH to ENABLE HUMAN SPACE EXPLORATION International Academy of Astronautics
    ARTIFICIAL GRAVITY RESEARCH TO ENABLE HUMAN SPACE EXPLORATION International Academy of Astronautics Notice: The cosmic study or position paper that is the subject of this report was approved by the Board of Trustees of the International Academy of Astronautics (IAA). Any opinions, findings, conclusions, or recommendations expressed in this report are those of the authors and do not necessarily reflect the views of the sponsoring or funding organizations. For more information about the International Academy of Astronautics, visit the IAA home page at www.iaaweb.org. Copyright 2009 by the International Academy of Astronautics. All rights reserved. The International Academy of Astronautics (IAA), a non governmental organization recognized by the United Nations, was founded in 1960. The purposes of the IAA are to foster the development of astronautics for peaceful purposes, to recognize individuals who have distinguished themselves in areas related to astronautics, and to provide a program through which the membership can contribute to international endeavors and cooperation in the advancement of aerospace activities. © International Academy of Astronautics (IAA) September 2009 Study on ARTIFICIAL GRAVITY RESEARCH TO ENABLE HUMAN SPACE EXPLORATION Edited by Laurence Young, Kazuyoshi Yajima and William Paloski Printing of this Study was sponsored by: DLR Institute of Aerospace Medicine, Cologne, Germany Linder Hoehe D-51147 Cologne, Germany www.dlr.de/me International Academy of Astronautics 6 rue Galilée, BP 1268-16, 75766 Paris Cedex 16,
    [Show full text]
  • Surviving in Space
    In This Guide What does the future hold for humans and space travel? Space is a one-of-a-kind exhibition that seeks to answer that question and more by exploring the challenges of living and working in space. Unlike traditional space exhibits that focus on the history of space travel, Space looks into current and future exploration. Take a journey to space through interactive exhibits, whole body experiences, and authentic artifacts that will engage you and your students with the unparalleled adventure of human space exploration. Your students will have the opportunity to: 1. Immerse themselves in the sights, sounds, and smells that astronauts experience while traveling and living in space; 2. Engage as problem solvers with some of the unique engineering challenges that must be solved to support living and working in space; TABLE OF CONTENTS 3. Experience what life is like in space through the voices of engineers, scientists and astronauts. In This Guide . 1 Space was produced in partnership with the International Space Exhibition Overview . 3 Station Office of NASA’s Johnson Space Center, the California Misconceptions About Space . 6 Science Center and the partner museums of the Science Museum Exhibit Collaborative. Connecting with the Classroom Pre-Visit . 11 Special thanks to Minnesota teachers who served as Guide advisors: Jill Jensen, Kim Atkins, Dee McLellan, Lynn Spears, Post-Visit . .16 Kate Watson, Brandi Hansmeyer. At the Museum Chaperone Guide . .22 Grades K–2 . .23 Grades 3–5 . .25 Grades 6–8 . .27 Grades 9–12 . 29 Resources for Teachers & Students . 31 Next Generation Science Standards . .33 Surviving in Space .
    [Show full text]