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

[单选题]
A student measures a di02vq)gv4qg hfl uouw8+g,og6 + / owvsstance four times. The readings are 3f*0ozf7kq 2t*e q, pps7.8 cm, 37.9 cm, 38.1 cm, 38.2 cm. What is,foq7p * *z0stpqefk 2 the best estimate 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. Theril1,*c7 y w,cd5sq 7i9hmgz yy+t (gx extremes (37.8 cm and 38.2 cm) are both 0.2 cm a i1wmg+ytz ir lydq7 ch9cs(,7g5*xy,way from the mean. So C is the correct answer.