本题目来源于试卷: Kognity IB Physics A.0 Measurements & Uncertainty,类别为 IBDP Physics
[单选题]
The length of a penci zt/4 yc6mb.( qzqs4od4ed; hxl is ezo):mzb.mk v.a;f: /1qgzb vmeasured using part of a measuring tape as shown below. k:zmbeqo.b1/m zgv;:f).vza  What is the length of the pencil?
A. $4.5 \pm 0.1 \; cm$
B. $11.5 \pm 0.2 \; cm$
C. $11.5 \pm 0.3 \; cm$
D. $11.5 \pm 0.5 \; cm$
参考答案: D
本题详细解析:
We should be looking at the cantrmyi3 n3l7j7 eb69ms wt* ua5/,utm scale! The uncertainty in a reading on a scale is usually taken as half the smallest division. Here the smallest division is 0.5 cm so we can read each point on the scale lmtb,n me/rtuw 35t37*unjiaa7ys96 to an accuracy of 0.25 cm. To find the length of the pencil we must take two measurements - one for each end of the pencil. This means that we must also add the uncertainties, giving an uncertainty of 0.5cm.
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