计算:98×91.
98×91,
=(100-2)×91,
=100×91-2×91,
=9100-182,
=8918.
丈量一段距离6次,结果分别为365.030m,365.026m,365.028m,365.024m,365.025m和365.023m。则观测值的中误差、算术平均值中误差和平均值的相对中误差分别为()。
A.±2.4m,±1.0mm,1/360000
B.±1.0mm,±2.4mm,1/150000
C.±1.1mm,±2.6m,1/140000
D.±2.6mm,±1.1mm,1/330000
人们有时要利用惯性,有时要防止惯性带来的危害,请你就以上两点各举一例。(不要求解释)
(1)___________________________________________________________________________;
(2)___________________________________________________________________________。