物理二轮复习试题弟2部分弟4讲.ppt

第4讲　高考中的图象问题 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 《考试大纲》能力要求中明确指出，要求学生具有阅读图象、描述图象、运用图象解决问题的能力．从近几年的高考情况来看，图象在高考中出现的频率很高，高考试题中均把物理图象作为重要的考查内容，从不同的侧面考查考生观察分析、收集信息、推理判断、作图处理数据和用图象解决物理问题的能力．高考中对图象的考查主要从以下几个方面来命题：(1)通过对物理过程的分析找出与之对应的图象并描绘；(2)通过对已知图象的分析寻找其内部蕴含的物理规律；(3)图象的转换——用不同的图象描述同一物理规律或结论；(4)综合应用物理图象分析解决问题． Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 1 运动学图象问题 建立物理模型 匀加速直线 匀速直线 匀减速直线 时间段(s) 0～2.5 2.5～11.5 11.5～14.0 平均加速度(m/s2) 0.40 0 0.40 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 请根据上表数据和所学知识判断下列图象(设F为手提包对电梯的压力，g＝9.8 m/s2)中正确的是(　　) Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 【解析】　根据表中电梯的运动情况，即确定A正确．B、D错误，根据牛顿第二定律，电梯匀加速上升时超重．匀减速上升时失重，可以确定C错误． 【答案】　A Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 2 电磁感应图象问题 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 【解析】　从正方形导线框下边开始进入到导线框下边完全进入磁场的过程中，导线框切割磁感线的有效长度逐渐增大，所以感应电流也逐渐增大，A项错误；从正方形导线框下边完全进入至下边刚穿出磁场边界时，切割磁感线有效长度不变，故感应电流不变，B项错；当正方形导线框下边离开磁场，上边未进入磁场的过程比正方形导线框上边进入磁场过程中，磁通量减少得稍慢，故这两个过程中感应电动势不相等，感应电流也不相等，D项错． 【答案】　C Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3 图象综合问题 图2 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty L