Kognity IB Physics A.0 Measurements & Uncertainty (id: 294aaa607)

admin

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 penc-zq9hja22xmt, 2d jesgas 1s(j)if 7y il is measured using part of ,frxk+zfr .mj74-1l(wqwt efu v q9-ba measuring tape as shown below.qk9 -r+wfujf vr7.,q xf(- 4elb1tzwm

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 reh +xm xsec/3y+ading 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 to an accuracy of 0.25 cm. To find the length of the pencil we must take two measurements - one fys+exx c3/hm +or each end of the pencil. This means that we must also add the uncertainties, giving an uncertainty of 0.5cm.