8.74. Set Up: The center of mass of each piece of length L is at its center. Solve: (a) From symmetry, the center of mass is on the vertical axis, a distance below the apex. (b) The center of mass is on the vertical axis of symmetry, a distance above the center of the hori-zontal segment. (c) Using the wire frame as a coordinate system, the coordinates of the center of mass are equal and each is equal to The center of mass is along the bisector of the angle, a distance from the corner. (d) By symmetry, the center of mass is at the center of the equilateral triangle, a distance above the center of the horizontal segment. 8.75. Set Up: The current mass of the earth is In this scenario, this mass came from an original earth of mass combining with and ejecting mass The mass is therefore given by the equation and The present orbital speed of the earth is its orbit circumference divided by its orbital period: Treat the Mars-sized body and the earth as an isolated system. Use coordinates where
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This note was uploaded on 03/06/2009 for the course PHYS 114 taught by Professor Shoberg during the Spring '07 term at Pittsburg State Uiversity.