[填空题]
The density of a solid sphere is measured withve1tg b2 8tuj7 perc .*xw,m sbr9gaentage uncertainty of 5%. The radius of the sphere is 4.0 ± 0.2 cm. What is the percentage uncertainty in the maswr ,.gb *asx9ms of the sphere? % (Please do not include the % simbol in the blank)
参考答案: 20.0
本题详细解析: The mass of the sphe1c2.s/jhs+dh6i o) b6z odslyre can be calculated by multiplying its volume by the density of the matebd1oss6c6iyzs h hlj./o2) +drial of which it is made: $$M=\frac{4}{3} \pi r^3 \rho$$ so the percentage uncertainty in $M$ is $$\frac{\Delta M}{M}=3 \frac{\Delta r}{r}+\frac{\Delta \rho}{\rho} .$$ The percentage uncertainty in $r$ is $5 \%$, so the percentage error in $M$ is $(3 \times 5 \%)+5 \%=20 \%$