小学、初中、高中各种试卷真题知识归纳文案合同PPT等免费下载www.doc985.com专题06机械能守恒定律能量守恒定律目录01机械能转化及守恒的判断····················································2考向一：机械能转化及守恒的判断········································································202机械能守恒定律的应用·····················································10考向一：机械能的图像类问题·············································································10考向二：单个物体的机械能守恒··········································································22考向三：多个物体(系统)的机械能守恒··································································2503能量转化及守恒定律的综合应用··········································30考向一：能量转化及守恒定律的综合应用······························································30考向四：涉及弹簧的能量问题·············································································34考向二：涉及板块、传送带的能量问题·································································49小学、初中、高中各种试卷真题知识归纳文案合同PPT等免费下载www.doc985.com01机械能转化及守恒的判断考向一：机械能转化及守恒的判断1．（2023·浙江·高考真题）一位游客正在体验蹦极，绑上蹦极专用的橡皮绳后从跳台纵身而下。游客从跳台下落直到最低点过程中（）A．弹性势能减小B．重力势能减小C．机械能保持不变D．绳一绷紧动能就开始减小【答案】B【详解】游客从跳台下落，开始阶段橡皮绳未拉直，只受重力作用做匀加速运动，下落到一定高度时橡皮绳开始绷紧，游客受重力和向上的弹力作用，弹力从零逐渐增大，游客所受合力先向下减小后向上增大，速度先增大后减小，到最低点时速度减小到零，弹力达到最大值。A．橡皮绳绷紧后弹性势能一直增大，A错误；B．游客高度一直降低，重力一直做正功，重力势能一直减小，B正确；C．下落阶段橡皮绳对游客做负功，游客机械能减少，转化为弹性势能，C错误；D．绳刚绷紧开始一段时间内，弹力小于重力，合力向下做正功，游客动能在增加；当弹力大于重力后，合力向上对游客做负功，游客动能逐渐减小，D错误。故选B。2．（2023·重庆·高考真题）（多选）某实验小组测得在竖直方向飞行的无人机飞行高度y随时间t的变化曲线如图所示，E、F、M、N为曲线上的点，EF、MN段可视为两段直线，其方程分别为和。无人机及其载物的总质量为2kg，取竖直向上为正方向。则（）A．EF段无人机的速度大小为4m/sB．FM段无人机的货物处于失重状态C．FN段无人机和装载物总动量变化量大小为4kg∙m/s小学、初中、高中各种试卷真题知识归纳文案合同PPT等免费下载www.doc985.comD．MN段无人机机械能守恒【答案】AB【详解】A．根据EF段方程，可知EF段无人机的速度大小为，故A正确；B．根据图像的切线斜率表示无人机的速度，可知FM段无人机先向上做减速运动，后向下做加速运动，加速度方向一直向下，则无人机的货物处于失重状态，故B正确；C．根据MN段方程，可知MN段无人机的速度为，则有，可知FN段无人机和装载物总动量变化量大小为12kg∙m/s，故C错...