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

[单选题]
A student measures a distanceeb: k9l () u.zua es5c)inri8y four times. The readin1sxg13uk5 qxv4 pi);v2 ukl /mi jxyr7gs are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate of ryxj s17l4g iixu/)v1kv ux2;pk3m5qthis 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 ez 7h/jwih: 1lvkh:6zz h0uu7 is 38.0 cm. The extremes (37.8 cm and 38.2 cm) are both 0.2 cm away from t7 iz:wjuhzk:1/lh v 0he u6zh7he mean. So C is the correct answer.