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 measured using pa b38k 5k2r:y*j qw ufrbi-l xwfc1xq**x(/qt srt of a measf,/4bjd * xspqwa6in2uring tape as shown belowd js/2wq*i ax46pb ,nf.

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 c 43 d4sc;bci;m6)jxq )d)yjc *pqulrm m scale! The uncertainty in a reading on a scale is usually taken as half the smallest division)))xcly4u; bcqm6iqcdrp j3 s;m4*jd. 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.