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 is measuredusqz-c ) /jt, 6ob9o0f zh;atj using part of a measuring tape as shown beh,uqrr sqf) l4q94+ml* 0 ;vr/avyfyelow.ylly huvq/esqfv044rr; q ,a) *fm9r+

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 uncertainty in a reading on am5,wf n7w cikl,rcp7c+u 64nl scale is usually taken as half the smallest division. Here thcl7 n6rmul4pi, 5fw+w,7c kc ne 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.