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 9pu p2pzc e7:/q5))gbzhohe((zhhp b me u .z 4qfw8v0piasured using part of a measuring tape as shown below p wq.z0iv4f 8u.  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 untbxg7h8c 7 ji2certainty 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 igc 8j2tbx77hthe 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.
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Post time 2024-8-21 21:38:19