文档介绍：第六章万有引力与航天第五节宇宙航行人教版必修 2 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 嫦娥奔月敦敦煌煌飞飞天天的的壁壁画画探究宇宙的奥秘,奔向遥远的太空。自古以来就是人类的梦想,怎样才能实现这一梦想呢? Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 一、牛顿的设想牛顿曾设想, 从高山上用不同的水平速度抛出物体,速度一次比一次大,则落点一次比一次远,如不计空气的阻力,当速度足够大时, 物体就永远不会落到地面上来,而围绕地球旋转,成为一颗人造地球卫星,简称。人造卫星由此可见,人造地球卫星运行遵从的规律是: 卫星绕地球做匀速圆周运动,地球对卫星的引力提供向心力。 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 探究问题一: 思考与讨论: 如图所示, A、B、C、D四条轨道中可以作为卫星轨道的是哪一条? 根据:卫星做圆周运动的向心力必须指向地心。 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 想一想:速度为多大时,物体将不会落回地面而成为绕地球旋转的人造卫星呢? ??卫星运动轨道特点: ?万有引力提供向心力,所以轨道平面一定经过地球中心,卫星围绕地球的中心做匀速圆周运动。 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 建立模型: 卫星绕地球做匀速圆周运动基本思路: 卫星绕地球做圆周运动的向心力由地球对卫星的万有引力提供。 G Mm r 2=m v 2r v= GM r 请同学们计算:已知地球半径 R=6400km ,地球质量 M= ×10 24kg,卫星在地面附近环绕地球作匀速圆周运动所必须具有的速度有多大? / GM v s R = = 二、宇宙速度 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose