Kognity IB Physics A.0 Measurements & Uncertainty (id: 294aaa607)

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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 pencil is meayj uqp2g aaa )(v9j p9cby*tnd0 7k8w,sured ni h oe7u5j1gl8 v/yuftc 95k,using part of a measuring tape as shown below7 u ej8ut icofl5hnv1g,/k59 y.

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 cm scale! The uncertainty in a reading on a scale ii 5 xgsr/wk3 a4s7*0(esodcz ss usually taken as half the smallest divisa/godx* 37e0ss crs( izws54kion. Here the smallest division is 0.5 cm so we can read each point on the scale 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.