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

[单选题]
A student measures a distarhdyx (cd 5-6tnce four times. The readings arl ,,2s-ctfs,z8wea-b vsm,iwe 37.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is the best estimate vtlz,a, ww8 ,2mes-ibsf-s, cof 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 extvqy9 3,i px 75u mlu9n*wcon;bremes (37.8 cm and 38.2 cm) are both 0.2 cm away from the mean. So C is the correct answexny3 ,iqu9bwv 7c*uno9pl;m 5 r.