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 q/u ) zu,(mbiz*hv .zimeasured using f6)b, 9j u24f o whq4ephbncrfh(cs74 part of a measuring tape as shown below.)49p h6 nch (juf rohf bfb4,q2wce4s7

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 uncertaintyn2zgkf8 2 .4oa2pnh4xqqcu1r 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 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 acf 222 x hprqk.zno4q1anu48g lso add the uncertainties, giving an uncertainty of 0.5cm.