Question

某同学在“研究匀变速直线运动”的实验中，用打点计时器记录了被小车拖动的纸带的运动情况，在纸带上确定出A、B、C、D、E、F、G共7个计数点，其相邻点间的距离如图1所示，每两个相邻的计数点之间的时间间隔为0.10s．                                                                                                                                        

                                                                                                                                                

（1）根据纸带上各个计数点间的距离，计算打下B、C、D、E、F五个点时小车的瞬时速度，并将各个速度值填在下面的横线上：（要求保留三位有效数字）                                                                              

v_B=                                                                                 m/s，v_C=          m/s，v_D=        m/s，v_E=              m/s，v_F=                                                                m/s；

（2）以A点为计时零点，将B、C、D、E、F各个时刻的瞬时速度标在如图2所示的坐标纸上，并画出小车的瞬时速度随时间变化的关系图线；                                                                                                  

（3）根据第（2）问中在画出的v﹣t图线，求出小车运动的加速度为         m/s²．（保留两位有效数字）                                                                                                                                 

Answer 1

故答案为：（1）0.400，0.479，0.560，0.640，0.721；（2）如图；（3）0.80