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 measured using pat6n*z( klevkidy *:u 0pxf.b2rt q:p)kbl:thpheffn h+0n r,/ l* q0kx46 9rqtwof a measuring tape as shown below.tfnh6 xl k/kr4,:tw+p :b0hr 09 pqf*he ql)qn

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 re0yz* 9-ndjs3xmr 2ypq ading on a scale is usuall3nrszm*pq9xj y2 y-d0y taken as 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.