Transcript Document
Week 10 1 What is the strength of the gravitational force with which the Earth pulls on you? MEarth = 5.98x1024 kg REarth = 6.37x106 m Week 10 QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 2 Astrologers believe that the forces of the planets and stars at the time of your birth determine key personality attributes and your fate in life. Could the force be gravity? What is the gravitational force with which Jupiter pulls on you when it is closest to earth? What is the gravitational force with which the person next to you pulls right now? MJupiter = 1.9x1027 kg djupiter = 7.78x1011 m dEarth = Week 10 1.5x1011 m QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 3 Astrologers believe that the forces of the planets and stars at the time of your birth determine key personality attributes and your fate in life. Could the force be gravity? What is the gravitational force with which Jupiter pulls on you when it is closest to earth? FJupiter on you = 2.4x10-5 N What is the gravitational force with which the person next to you pulls right now? Fclassmate on you = 3.8x10-5 N MJupiter = 1.9x1027 kg djupiter = 7.78x1011 m dEarth = Week 10 1.5x1011 m QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. 4 Week 10 5 What is the escape speed of a particle on the “surface” of the sun? QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Week 10 6 Sagittarius A* is a bright radio source. What is the mass of Sag A*? How many times the mass of the sun is this? 1 light day = 2.6x1013 m 1 year πx107 sec Msun = 2x1030 kg Week 10 7 Week 10 8 Week 10 9 A particle is undergoing simple harmonic motion. What are its • Amplitude? • Period? • Angular frequency? • Maximum velocity? • Phase constant? 6 5 4 3 position [m] 2 1 0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 -1 -2 -3 -4 -5 -6 time [sec] Week 10 10 A 160 g mass on a 1.0 m-long string is pulled 6.7o to one side and released. How long does it take for the pendulum to reach 2.9o on the opposite side? QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Week 10 11 The 20 cm-long wrench in the figure swings on its hook with a period of 0.88 s. When the wrench hangs from a spring of spring constant 350 N/m, it stretches the spring 3.5 cm. What is the wrench's moment of inertia about the hook? QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Week 10 12 The 15 g head of a bobble-head doll oscillates in SHM at a frequency of 4.0 Hz. QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. * What is the spring constant of the spring on which the head is mounted? * Suppose the head is pushed 2.0 cm against the spring, then released. What is the head's maximum speed as it oscillates? Week 10 13 Week 10 14