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 id b hj,wn;:7kks measured u, rf7yhn6 2tjc y1lrh8sing part of a measuring tape as shown below.rhytrh ln y28c7, 1f6j

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 aw blh/6n9 0jeh a *d5o/9oplde+mff+e,h z-yat 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 h5/0e6-b nalff9ld +zy9a ed+joh*owp, /m ehscale 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.