本题目来源于试卷: Kognity IB Physics A.0 Measurements & Uncertainty,类别为 IBDP Physics
[单选题]
A student measures two lezyy 0 2rmsy/1ungths as follows:5,xceww rg,+o $$a = (10 \pm 0.1) \; cm$$ $$b = (20 \pm 0.1) \; cm$$ Which of the following quantities has the largest percentage uncertainty?
A. $a$
B. $b$
C. $a+b$
D. $a-b$
参考答案: D
本题详细解析:
The largest percentage uncertainty will result fromqc . f ls5h30io6s8mqreq2idt ;tk(:b the largest absolute uncertainty divided by the smallest measurement value. A and B have an absolute uncertainty of 0.1 cm, while for C & D it is 0.2 cm. So the percentage uncertainties are: A 1%; B 0.5%; C 0.67%; .rqei:5 b(qqs2i6lm ; 8t ot0 fkcs3dh and D 2%. Clearly D is the largest.
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