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 iscne*k7w 5t43 yaogjk * measured usi+1yafoi,e 8tmx7v z4r ng part of a measuring tape as shown below.x8 if1 ,zvmr +e47otay

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 atn xqfix)bl*a , . .a+r xuf2yw7yq)ga/ the cm 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 to an accuracy of 0.25 cm. To find the length of the pencil we must take two measurements - oneyx*/+ .7nyb xia ) .gu)f2law,f raqqx for each end of the pencil. This means that we must also add the uncertainties, giving an uncertainty of 0.5cm.