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

[单选题]
A student measures a dqe*;- l8unrix+q;j y 9 hj5ubnisfolh(sjx h4tmd(s ))f gn h3-;tance four times. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimaxt)s-ffmhg s(34donjh l); (hte 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. T(g2 sj: m9imoy-kv.jhz4g s(she extremes (37.8 cm and 38.2 cm) are both 0.2 cm away from the mean. So 2(4 (.o gzh gm :ms9sk-jjyivsC is the correct answer.