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

[单选题]
A student measures a disieh18dpb w1nwrl b+vmu. iam m+95r//xi,pm0tas8*sl:3e 4xhgyoly +zo -tuh4nce four times. The readings are 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate of this measure 3oyeg4ut*x s-hs4o+hy8lz:l ment?

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 f2t tcax-(z)un 4tos :(37.8 cm and 38.2 cm) are both 0.2 cm away from t)n(o4asu:c zxt- tf2the mean. So C is the correct answer.