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

[单选题]
A student measures a distanceye 7i,(y:xde g p x.v-u1htl6e/2 o zhlfour times. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate of th6-zt lvuophl1e h/2x. is 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 a8osl5f8).dfsr1qo)s y f+g uis 38.0 cm. The extremes (37.8 cm and 38.2 cm) are both 0.2 cm away so+uff r.gs8dyaf)5o8 l1 )sqfrom the mean. So C is the correct answer.