Transcript mayreview2
Review for Exam 2 Chapters 5,6,7,8 PHYS 1050 May, 2002 Purpose • This document is a study guide, NOT a comprehensive list of all topics included on the exam. • The exam will cover material from both the text, class notes, and lecture demonstrations. • SUMMARY and REVIEW AND DISCUSSION at the end of the text chapters are also good sources of information and comprehension assessment. Equations and Constants • • • • F = ma Fgrav = Gm1m2/r2 P2 = a3 or (M+m) P2 = a3 M = rv2/G where M=mass of planet, r=radius of moon’s orbit, v=circular orbit speed • • • • • • • • • circumference of circle = 2 x radius = 2 r diameter = D = 2 x radius OR D = 2r area of circle = r2 = (D/2)2 volume of sphere = 4/3 r3 = 4/3 (D/2)3 density = mass/volume distance = speed x time 3600 in a circle light gathering power proportional to area of objective (or D2) angular resolution proportional to wavelength of light studied and inversely proportional to diameter of objective. •Properties of Telescopes – light gathering power proportional to area of primary or (diameter)2 – resolution as a function of diameter of the objective and the wavelength of light imaged •Types of Telescopes and Detectors: – understand advantages/disadvantages of each type •reflectors (mirrors, large size) •refractors (lenses) •space-based telescopes – Earth’s atmosphere interferes with ground based observations – wavelengths absorbed, reflected, transmitted – turbulence •radio telescopes •infrared, ultraviolet, and high energy telescopes – design of telescope •detectors – eye – photographs (chemical recorders) – CCDs (electronic recorders) •Solar System – Age of the solar system: ~ 4.6 billion years old – Know the ordering of the planets from the Sun. – Know which planets are the terrestrial planets, which are the jovian planets, and which fit neither category. – Be aware of and understand the primary differences between terrestial and jovian planets. Use TABLE 6.2 in your textbook. – Know the approximate relative sizes and masses of the planets. Look at the appropriate columns in TABLE 6.1. – Know how the average densities of the planets compare (see "DENSITY" in TABLE 6.1) – Know the approximate rotational period of the planets -- know which are "slow", which are "medium", and which are "fast" rotators. – Understand physical differences between comets, asteroids, and meteoroids. – Know which planets have been visited by spacecraft and on which objects have spacecraft actually landed. Develop a sense of how each planetary exploration mission changed our perspective and understanding of the properties of each planet. • for example: What did Magellan add to our knowledge of Venus? What about Viking with respect to Mars ? •Formation of Planetary Systems – List the main features of our solar system that a theory of the formation of the solar system must explain. – Outline the process by which planets are formed as a normal by-product of star formation. •Condensation theory –Role of dust –Accretion –Fragmentation –Formation of giant planets –Temperature and distance from the Sun – Differentiation •Entire solar system •Individual planets – Extra-solar planets •Method of discovery •Comparison with our solar system •PLANET EARTH – Know the basic “spheres" into which planetary scientists have divided up the Earth: • lithosphere, hydrosphere, atmosphere, magnetosphere, biosphere • composition, density, temperature trends in each region • Interactions between spheres – Know the different regions of the Earth's atmosphere: • names, main features, ordering with altitude • temperature variation with altitude – Define P-waves and S-waves. • What information is derived from studying seismic waves? – Understand the term "plate tectonics". • Know what process drives plate tectonics. • Know that most geological activity (e.g., earthquakes, volcanoes) is associated with plate boundaries. • New crust is created at plate boundaries by upwelling mantle material. • Old crust is returned to the mantle in subduction zones. • Lighter continental crust "floats" on the more dense crust of the ocean basins. – Know the definition of a "half-life" for a radioactive element. – Know where the Earth's magnetosphere exists and what effect it has on atomic particles blowing past Earth in the solar wind. – Understand the source of the tides and their effect on the the Earth's rotation. •THE MOON – Understand the difference between the highlands and maria on the moon. • Which is the older feature? • How do we know which is older? – Know that the Moon rotates once about its axis for each orbit about Earth. • Understand why this must be true if we see only one side of the moon. • How is the Earth-Moon separation changing? Why is it changing? • What is the final relative orbital and spin rate for the Earth and Moon? – Know the relative size and mass of the Earth and Moon. – Know the distance to the Moon. – Understand the origin of lunar craters, and their relative distribution on the lunar surface. • Are there more craters on the maria or highlands? – Know if the Moon has an atmosphere. – Understand the current concept of the lunar interior. • depth of the crust, • nature of the Moon's mantle, • nature of the Moon's core. – Understand the phases of the Moon as seen from Earth. – Compare spheres of Moon to those of the terrestrial planets. •MERCURY – Mercury is the closest planet to the Sun. – Describe the rotation and orbital period of Mercury. •seasons, elliptical orbit, spin-orbit resonance – Describe the surface of Mercury: craters? volcanoes? oceans? •Know what is meant by "scarps" on Mercury; how they may have formed. – How is Mercury’s surface different/similar to that of the Moon. – How does the density of Mercury compare to that of the Earth? Moon? – Does Mercury have an atmosphere? magnetic field? •Explain. – Does Mercury have a magnetic field? •Explain. – Compare the spheres on Mercury to those of other terrestrial planets and Earth’s Moon.