Kognity IB Physics A.0 Measurements & Uncertainty (id: 87ba97ed9)

[单选题]
A student measures a distance four times. The readings2 0kjrqu0 5mzx*0bkxa5qf pvgd69yv2 azv4ucq5jzbpyl: ; bn.3e:g0x re 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estc4x30;nj lb 5b. :zqup zyv:egimate of this measurement?

A. $37.8 \pm 0.2 \; cm$
B. $37.8 \pm 0.4 \; cm$
C. $38.0 \pm 0.2 \; cm$
D. $38.2 \pm 0.4 \; cm$


参考答案:  C


本题详细解析:
The mean of the measurements is 38.0 cm. The extremes (37.1e:0zer ht0j+k gsh u18 cm and 38.2 cm) are both 0.2 cm away 0rksh0uj eh 1+1z e:gtfrom the mean. So C is the correct answer.