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 part of a measuri r9ww)i 2k*hn xng t c jx5ex:t*7dfape as shown below. e 5fjtd:x*xc 7 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 x4 2lut)j. vcp-if7 ficm 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 t 4fjtp li-v7xu .2ci)fo 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