Kognity IB Physics A.0 Measurements & Uncertainty (id: d206553aa)

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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 time for two events, a an,fxtq/0x.mr r d b, are mea),q,cb -lok sc2z+guev2w;g- f nz0yhsured to be $(5.1 \pm 0.1)s$ and $(4.9 \pm 0.1)s$ respectively. In which of the following quantities is the fractional(percent) uncertainty the smallest?

A. $a+b$
B. $a-b$
C. $a \times b$
D. $a/b$


参考答案:  A


本题详细解析:
C and D will both haveltv 36 s lk(/(a6;loi*wrdj zv-whr +r identical fractional uncertainties. They cannot both be the smallest, so they must both be incorrect. A and B will have the same absolute uncertainty (0.2 s), but A is a large number (10) compared to B (0.2).r*-oti l/llva (rzvrd 6skwwh3;+ j(6 Hence fractional uncertainty of A is the smallest.