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 pencil is measured using pags, : -6wy.rb .ntcomzrt/bi7,it 1gr mgv9a yze00 jpl/ of a measuring tape as shown below.t 7,vrai gip/10elbyg9 z/jm 0

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 a scax +ws p.-*w4lsduf c9ble 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-cs x*lb9wsu.p+ f4dw 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.