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 us *-lzlb cx*jh:lnd59um -( sk hing part of a measur xzyv iesawu//mk+ 291ing tape as shown below yv +ksiu/zm e1w92/xa.  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 lookingu +2-nwjt teb2 at 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 - one for each end of the pencil. This means that we must also add t2 nj eb-+tw2uthe uncertainties, giving an uncertainty of 0.5cm.
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Post time 2024-8-21 21:38:19