本题目来源于试卷: Kognity IB Physics A.0 Measurements & Uncertainty，类别为 IB物理学
[单选题]
The length of a pencil is measured n ub4cgo.vv1.j r4a/eusing part of a meas ru9smz)z.o1i dye6)8d2n qui uring tape as shown below. si8d1io 9mnd) qyzuru26z.) e 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 k+.hub2wp, t othe cm scale! The uncertainty in a reading on a scale is usually taken apt uoh2+ .k,wbs 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 the uncertainties, giving an uncertainty of 0.5cm.
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