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1问题的提出人造地球卫星沿椭圆形轨道绕地球运行,近地点A到地球中心C的距离为r1,远地点B到地球中心的距离为r2,卫星在近地点A处的速率为vA,卫星在远地点B处的速度vB多大?学生:利用万有引力提供向心力,GMm/r12=mvA2/r1,GMm/r22=mvB2/r2,v B=vA(r1/r2)~(1/2).评析:学生利用万有引力提供向心力产生向心加速度的分析思路是正确的.在最初学习开普勒行星运动定律时教材也明确提出将行星轨道按
1 PROBLEM PROPOSALS Artificial Earth satellites orbited the Earth along an elliptical orbit. The distance between perigee A and center C is r1, the distance between apogee B and the earth’s center is r2, the satellite’s velocity at a perigee A is vA, and the satellite’s position at apogee B At the speed of vB students: the use of gravitation to provide centripetal force, GMm / r12 = mvA2 / r1, GMm / r22 = mvB2 / r2, v B = vA (r1 / r2) Provide centripetal force to produce centripetal acceleration analysis of the train of thought is correct in the initial study of Kepler’s laws of planetary motion when the text also made it clear that the planetary orbit