Question

在研究小球平抛运动的实验中，用闪光照相机照相记录其轨迹，已知每次照相的时间间隔均为T，已有照片(如图所示)的三个点的坐标，少一个抛出点的像，请写出抛出点1的坐标：x₁=____；y₁=____．

Answer 1

答案：
解析：

设计意图：本题考查基本实验，研究小球平抛运动的理解和掌握情况． 解析：在水平方向，有： x3-x2=v0T                                                                                                                ① x2-x1=v0T                                                                                                                ② 则：①-②得：x3-x2-x2+x1=0 解得：x1=2x2-x3 在竖直方向，有： (y4-y3)-(y3-y2) =gT2                                                                                                                                                                                                ③ (y3-y2)-(y2-y1) =gT2                                                                                                                                                                                                ④ 则：③-④得：y1=y4-3(y3-y2) 易错点：要充分利用水平方向是匀速直线运动，竖直方向上是自由落体运动这一特性，否则易错． 答案：(2x2-x3)；y4-3(y3-y2)