[填空题]
The radius of a circir) myfb nzw 3p/ju039le ofqq 1 cn1i h+ tt c9,fd3vg1r)w.bh/zmi wire is measured to be 10.0 ± 0.5 cm. What is the percentage error in the area of the loop? % What is the percentage error in the circumference of the loop? %
参考答案: 空格1: 10.0
空格2: 5.0
本题详细解析: First calculate the peivoy +1lw j,(prcentage error in the radius of the loop: $$ \frac{\Delta \mathrm{r}}{\mathrm{r}}=\frac{0.5}{10}=5 \% $$ The area of a circle is $A=\pi r^2$ and so the percentage error on the area of the loop will be twice the percentage error of the radius, $\Delta A=10 \%$.