梁国际 2019-05-31 21:59
<p class="pl_nr" style="margin-top: 0px; margin-bottom: 0px; padding: 0px; border: 0px; line-height: 24px; font-size: 12px; color: rgb(51, 51, 51); font-family: 微软雅黑; white-space: normal; background-color: rgb(255, 255, 255); word-wrap: break-word;"><br/></p><p style="margin-top: 0px; margin-bottom: 0px; padding: 0px; border: 0px; line-height: 26px;"><span style="margin: 0px; padding: 0px; border: 0px; display: inline-block; color: rgb(51, 51, 51); font-family: 微软雅黑; font-size: 12px; background-color: rgb(255, 255, 255);">牛顿第一定律不是直接由实验得出的，必须分析透伽利略的理想斜面实验，明白不用力物体也能做匀速直线运动。<span style="color: rgb(51, 51, 51); font-family: 微软雅黑; font-size: 12px; background-color: rgb(255, 255, 255);">教师要注意引导学生针对牛顿第一定律内容中的“一切”、“没有受到力的作用”、“总保持”、“或”的含义加深认识。明确力和运动的关系，即力是改变物体运动状态的原因，而力不是维持物体运动的原因。</span></span><br/></p><p><span style="margin: 0px; padding: 0px; border: 0px; display: inline-block; color: rgb(51, 51, 51); font-family: 微软雅黑; font-size: 12px; background-color: rgb(255, 255, 255);"><br/></span></p><p><br/></p><p><br/></p>
陈华丽 2019-05-13 09:59
<p><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: 宋体;"><span style="font-family:宋体">通过实验演示帮助确立</span></span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: "Times New Roman";">“</span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: 宋体;"><span style="font-family:宋体">力是改变运动状态的原因</span></span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: "Times New Roman";">”</span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: 宋体;"><span style="font-family:宋体">的概念,再通过推理建立</span></span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: "Times New Roman";">“</span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: 宋体;"><span style="font-family:宋体">不受力运动状态不变</span></span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: "Times New Roman";">”</span><span style="margin: 0px; padding: 0px; color: rgb(102, 102, 102); font-size: 10.5pt; text-indent: 28px; background-color: rgb(255, 255, 255); font-family: 宋体;"><span style="font-family:宋体">的概念。</span></span></p>