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

[单选题]
The time for two events, a aolo:i6c2g - iln s06fznd b, are measured t-5;g( oxz 9 tyrdhux;vo 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 have identical fractional uncertainties. They cannot both yh0u4ae,2z czd,s9hv/o4 5g 6qyl enpbe 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) compa5 d/qp hy9 oaln2 0zz6,cush4ey,4g vered to B (0.2). Hence fractional uncertainty of A is the smallest.