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2005年江苏物理高考第5题:某人造卫星运动的轨道可近似看作是以地心为中心的圆.由于阻力作用,人造卫星到地心的距离从r_1慢慢变到r_2,用E_(k1),E_(k2)分别表示卫星在这两个轨道上的动能,则( ) A.r_1r_2 E_(k1)E_(k2) D.r_1>r_2 E_(k1)>E_(k2) 解析假设轨道半径不变,卫星受大气阻力作用使线速度减小,因而需要的向心力减小,而提供的向心力(万有引力没变)大于需要的向心力,所以卫星将
In 2005, the fifth issue of the Jiangsu Physical Education College Entrance Examination: The orbit of an artificial satellite can be approximated as a circle centered on the center of the earth. Due to the resistance, the distance from the artificial satellite to the center of the earth changes slowly from r_1 to r_2, with E_ ( K1), E_(k2) respectively represent the kinetic energy of the satellite in these two orbits, then () A.r_1r_2 E_(k1)E_(k2) D.r_1>r_2 E_(k1)>E_(k2) Assume that the orbital radius is constant and that the satellite is affected by the atmospheric resistance and the linear velocity is reduced, so the required centripetal force is reduced. Small, and the provided centripetal force (gravitational gravity has not changed) is greater than the required centripetal force, so the satellite will