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

[单选题]
A student measures a gs0 ta j*)m (nrq2 a8m0e.wpjmdistance four times. The reading:c af mti1.p4rs are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best emrc 1tp.ai f:4stimate 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 (37.8 cm and 38)-pcnbnow tp (4imq j(i(cq2 -.2 cm) are both 0.2 cm away from tc( 2i q(pwnpji) (nm 4qb-o-cthe mean. So C is the correct answer.