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

[单选题]
The time for two events, a and b, u4l 0h-sghk 9drk-qiguhxu)m9,*3rz lc x)+,8 qknkc6w,rs oare measured 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 have identical fractional:ybb cc b53-eq5iv6 ghd:oxy. 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). Hence fracti:v.b5c- qxbo hyeb:5cd g3i6yonal uncertainty of A is the smallest.